Federal Executive Branch
Here's a look at documents from the U.S. Executive Branch
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White House Fact Sheet: Bolstering National Security
WASHINGTON, April 3 -- The White House issued the following fact sheet on April 2, 2026:
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President Donald J. Trump Bolsters National Security and Strengthens U.S. Supply Chains by Imposing Tariffs on Patented Pharmaceutical Products
BOLSTERING NATIONAL SECURITY: Today, President Donald J. Trump imposed tariffs on patented pharmaceuticals and their ingredients under Section 232 of the Trade Expansion Act of 1962 to bolster American national security and public health.
* President Trump imposed a 100% tariff on patented pharmaceutical products and ingredients.
* The tariffs will come into
... Show Full Article
WASHINGTON, April 3 -- The White House issued the following fact sheet on April 2, 2026:
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President Donald J. Trump Bolsters National Security and Strengthens U.S. Supply Chains by Imposing Tariffs on Patented Pharmaceutical Products
BOLSTERING NATIONAL SECURITY: Today, President Donald J. Trump imposed tariffs on patented pharmaceuticals and their ingredients under Section 232 of the Trade Expansion Act of 1962 to bolster American national security and public health.
* President Trump imposed a 100% tariff on patented pharmaceutical products and ingredients.
* The tariffs will come intoeffect in 120 days for certain large companies, and 180 days for smaller companies.
* Trade Deal Countries:
- If a pharmaceutical product is from the European Union, Japan, Korea, or Switzerland and Liechtenstein, a 15% tariff will apply. If a pharmaceutical product is from the United Kingdom, a lower tariff will apply, subject to the recently concluded UK pharmaceutical agreement.Onshoring and pricing agreements:
= For companies that enter into Most Favored Nation (MFN) pricing agreements with the Department of Health and Human Services (HHS) and onshoring agreements with the Department of Commerce, a 0% tariff will apply through January 20, 2029. For companies that only enter into onshoring agreements with the Department of Commerce, a 20% tariff will apply.The Department of Commerce and HHS will provide pathways for companies to enter into onshoring and MFN pricing deals with the U.S. Government.
- Generic pharmaceuticals: Generic pharmaceutical products, biosimilars, and associated ingredients are not subject to tariffs at this time. This will be reassessed in one year.
* Specialty pharmaceutical products: Orphan drugs, drugs for animal health, and certain other specialty pharmaceutical products will be exempt, if they are from trade deal countries or meet an urgent public health need.
* The Proclamation establishes strong monitoring and enforcement mechanisms, including external audits and tariff increases on future and past imports.
STRENGTHENING AMERICAN SUPPLY CHAINS: President Trump recognizes that America must manufacture pharmaceutical products in order to be safe, secure, and healthy.
* President Trump imposed these tariffs following an extensive investigation conducted by the Secretary of Commerce under Section 232 of the Trade Expansion Act of 1962, as amended, to determine the effects on national security of imports of pharmaceuticals, pharmaceutical ingredients, and related products.
* The investigation found that patented pharmaceuticals and associated pharmaceutical ingredients are being imported into the United States in such quantities and under such circumstances as to threaten to impair our national security.
* The impending Section 232 tariffs have already spurred approximately $400 billion in new investment commitments from U.S. and foreign pharmaceutical companies, which will be spent in the United States during President Trump's current term in office.
* A self-sufficient domestic manufacturing and industrial base for pharmaceutical products is vital for the ability to support national defense requirements and public health.
* Despite being the world leader in research and development for most innovative pharmaceuticals, the U.S. is heavily reliant on imports, threatening to limit U.S. access to life-saving medications in the event of global supply chain disruption.
BUILDING ON PROMISES KEPT TO PUT AMERICA FIRST: This action builds on President Trump's commitment to put America first, protect our national security, and strengthen American manufacturing across all sectors.
* In May 2025, President Trump signed an Executive Order to remove regulatory barriers and facilitate the restoration of a robust domestic manufacturing base for prescription drugs, including key ingredients and materials necessary to manufacture prescription drugs.
* In August 2025, President Trump signed an Executive Order to ensure American pharmaceutical supply chain resilience by filling the strategic active pharmaceutical ingredients reserve.
* President Trump's Administration has launched Section 232 investigations in adjacent sectors such as personal protective equipment, medical consumables, and medical equipment and devices, as well as robotics. These investigations will help ensure that harmful imports in any strategic sector do not compromise national security.
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Original text here: https://www.whitehouse.gov/fact-sheets/2026/04/fact-sheet-president-donald-j-trump-bolsters-national-security-and-strengthens-u-s-supply-chains-by-imposing-tariffs-on-patented-pharmaceutical-products/
White House Fact Sheet: Bolstering Domestic Manufacturing of Strategic Metals and Their Derivatives
WASHINGTON, April 3 -- The White House issued the following fact sheet on April 2, 2026:
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President Donald J. Trump Strengthens Tariffs on Steel, Aluminum, and Copper Imports
BOLSTERING DOMESTIC MANUFACTURING OF STRATEGIC METALS AND THEIR DERIVATIVES: Today, President Donald J. Trump signed a Proclamation to strengthen tariffs imposed on imported steel, aluminum, and copper in order to more effectively address the national-security threat posed by such imports.
* The Proclamation defines the way that tariffs are assessed, ensuring that they reflect the full value of imported steel, aluminum,
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WASHINGTON, April 3 -- The White House issued the following fact sheet on April 2, 2026:
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President Donald J. Trump Strengthens Tariffs on Steel, Aluminum, and Copper Imports
BOLSTERING DOMESTIC MANUFACTURING OF STRATEGIC METALS AND THEIR DERIVATIVES: Today, President Donald J. Trump signed a Proclamation to strengthen tariffs imposed on imported steel, aluminum, and copper in order to more effectively address the national-security threat posed by such imports.
* The Proclamation defines the way that tariffs are assessed, ensuring that they reflect the full value of imported steel, aluminum,and copper products--not an artificially low foreign price.
* The Proclamation also establishes clear rules for calculating Section 232 metals tariffs.
- Articles made entirely or almost entirely of aluminum, steel, or copper will pay a flat 50% on their full value -- for example, steel coils and aluminum sheet.
- Derivative articles substantially made of steel, aluminum, or copper will pay a flat 25% on their full value.
- Certain metal-intensive industrial equipment and electrical grid equipment will pay 15% through 2027, to accelerate the massive industrial base buildout currently underway across the United States.
- Products made abroad but entirely with American steel, aluminum, and copper will be subject to lower tariffs of 10%.
- Products made of 15% or less steel, aluminum, or copper will no longer be subject to Section 232 metals tariffs.
STRENGTHENING ECONOMIC AND NATIONAL SECURITY: President Trump has strengthened tariffs on imported aluminum, steel, and copper to protect the national security of the United States, including the economic resilience of vital industries and the financial position of American workers.
* In 2025, the United States became the third largest steel producing nation in the world, surging past rival economies--thanks to President Trump's Section 232 tariffs program. New steel plants are being built in America, for the first time in a generation, revitalizing our great steel communities and providing good-paying jobs for American workers.
- Over 4 million tons of new crude steelmaking capacity is expected to become operational in the next two years, including in West Virginia, Arkansas, and South Carolina, with additional investments underway across the country.
* New U.S. aluminum and copper smelting is also underway across America. Earlier this year, Century Aluminum and Emirates Global Aluminum announced a joint venture to build the first new aluminum smelter in the United States in decades, in Oklahoma. Companies such as Highland Copper, Ivanhoe Electric, Rio Tinto, and Wieland are expanding U.S. copper mining, smelting, and fabrication facilities.
* This buildout -- and the continued health of these vital American industries -- is only possible through the continued implementation and strengthening of the President's Section 232 tariff programs. These tariffs ensure domestic producers and workers can compete on a level playing field.
PUTTING AMERICAN PRODUCTION FIRST: Today's Proclamation builds on previous actions taken by President Trump that strengthen national security while uplifting the economic position of American workers, families, and communities.
* In his first term, President Trump revolutionized international trade by using Section 232 to tariff steel and aluminum imports -- addressing decades of short-sighted, globalist trade policies that had allowed these domestic industries to weaken.
* In February 2025, President Trump issued a historic Proclamation overhauling the steel and aluminum tariffs, including by eliminating hundreds of thousands of product-specific exceptions and country-specific exemptions that had accumulated during the Biden years.
* In June 2025, President Trump boldly increased the steel and aluminum tariff rates to 50% -- a level strong enough to ensure the strengthening of these critical industries.
* In July 2025, President Trump issued a historic proclamation adding copper to the Section 232 tariffs program, at the same 50% rate as steel and aluminum.
* Through the strategic use of tariffs, President Trump has, among other things, brought hundreds of billions of dollars back to the American people and promoted foreign investment in American commerce and American workers.
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Original text here: https://www.whitehouse.gov/fact-sheets/2026/04/fact-sheet-president-donald-j-trump-strengthens-tariffs-on-steel-aluminum-and-copper-imports/
USSTRATCOM Hosts Aurora Pulse Electromagnetic Spectrum Exercise
OFFUTT AIR FORCE BASE, Nebraska, April 3 -- The U.S. Strategic Command issued the following news on April 2, 2026:
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USSTRATCOM hosts Aurora Pulse electromagnetic spectrum exercise
U.S. Strategic Command hosted operations and planning officers from the uniformed services, unified commands, Joint Staff, and additional government agencies for a first-of-its-kind electromagnetic spectrum tabletop exercise, Aurora Pulse, March 24-26 in the Gen. Curtis LeMay Command and Control Facility here.
The participants gathered to tackle the robust challenges of electromagnetic spectrum operations during
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OFFUTT AIR FORCE BASE, Nebraska, April 3 -- The U.S. Strategic Command issued the following news on April 2, 2026:
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USSTRATCOM hosts Aurora Pulse electromagnetic spectrum exercise
U.S. Strategic Command hosted operations and planning officers from the uniformed services, unified commands, Joint Staff, and additional government agencies for a first-of-its-kind electromagnetic spectrum tabletop exercise, Aurora Pulse, March 24-26 in the Gen. Curtis LeMay Command and Control Facility here.
The participants gathered to tackle the robust challenges of electromagnetic spectrum operations duringcrisis and conflict. These challenges, compounded by the austere setting of the exercise, included not only contested use by adversary forces, but also congested access due to expanded spectrum allocation to commercial and civilian systems.
USSTRATCOM Deputy Commander U.S. Air Force Lt. Gen. Michael Lutton addressed participants prior to the exercise kickoff.
"Electromagnetic spectrum considerations must be central in defense planning," said Lutton. "Our adversaries operate in the spectrum, so our freedom of action in the operating environment is strengthened by maintaining EMS superiority."
During the exercise, participants walked through two days of scenarios, testing their procedures, tactics and operations in a degraded and contested environment.
"EMS is critical in today's fight," said Lutton. "It is imperative our warfighters be able to operate and win in a highly-contested environment."
U.S. Air Force Maj. Gen. AnnMarie Anthony, USSTRATCOM's Joint Electromagnetic Spectrum Operations Center director, framed the goal of Aurora Pulse.
"The end goal is to learn what, and who, to ask about EMSO," said Anthony. "Today, the EMS environment is evolving rapidly, becoming increasingly congested and contested. This congestion poses significant challenges for both military and civilian operations."
USSTRATCOM is directed in the Unified Command Plan to oversee electromagnetic spectrum operations.
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Original text here: https://www.stratcom.mil/Media/News/News-Article-View/Article/4449769/usstratcom-hosts-aurora-pulse-electromagnetic-spectrum-exercise/
MICC Contracting Professionals Support Fort Stewart Mobilization Exercise
REDSTONE ARSENAL, Alabama, April 3 -- The U.S. Army Contracting Command issued the following news on April 2, 2026:
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MICC contracting professionals support Fort Stewart mobilization exercise
By Tish Williamson
FORT STEWART, Ga-- The 904th Contracting Battalion participated in a Mobilization Force Generation Installation (MFGI) tabletop exercise March 24-25 at Fort Stewart, bringing together Army and National Guard partners to strengthen deployment readiness and contracting integration.
The mobilization exercise, chaired by Brig. Gen. Jason Fryman, Assistant Adjutant General for the Georgia
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REDSTONE ARSENAL, Alabama, April 3 -- The U.S. Army Contracting Command issued the following news on April 2, 2026:
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MICC contracting professionals support Fort Stewart mobilization exercise
By Tish Williamson
FORT STEWART, Ga-- The 904th Contracting Battalion participated in a Mobilization Force Generation Installation (MFGI) tabletop exercise March 24-25 at Fort Stewart, bringing together Army and National Guard partners to strengthen deployment readiness and contracting integration.
The mobilization exercise, chaired by Brig. Gen. Jason Fryman, Assistant Adjutant General for the GeorgiaArmy National Guard. The event focused on synchronizing efforts across organizations responsible for preparing units for deployment was attended by approximately 40 personnel from nearly a dozen commands and staff agencies across the base.
The 904th CBn is part of the 419th Contracting Support Brigade, one of three brigades under under the Mission and Installation Contracting Command, responsible to provide critical contracting services to units during troop mobilization. MICC itself is a subordinate command of the Army Contracting Command and the Army Materiel Command, ensuring that contracting operations align with Army-wide priorities. MICC-Fort Stewart is one of 35 installation contracting offices assigned to the MICC across 34 locations around the globe.
Maj. Jack Konrat, a contracting officer with the 904th CBn and MICC-Fort Stewart contracting office, delivered a comprehensive overview of MICC capabilities, emphasizing the scope of contracting support available to mobilizing units.
"The MICC provides critical contracting capabilities that enable commanders to sustain operations from the earliest stages of mobilization," Konrat said. "Our role is to ensure units have the resources they need, when they need them, to remain mission ready."
The central topic of the exercise was identifying and mitigating potential gaps in Logistics Civil Augmentation Program support during early phases of mobilization. Officials highlighted the 904th Contracting Battalion's role in bridging those gaps until LOGCAP reaches full operational capability.
Lt. Col. Stephen Lawson, who has served as the 904th battalion commander since July 2025, said the involvement of contracting professionals in the exercise was crucial for ensuring a smooth and efficient mobilization process for all involved units.
"Exercises like this allow our team to align expectations and close seams before they impact operations," Lawson said. "The 904th's involvement in the earliest stages of planning ensures contracting support is synchronized with unit timelines, budgets and needs, which directly contributes to unit and Soldier readiness."
He lauded Konrat for effectively integrating his contracting expertise into the mobilization planning, ensuring the 904th Contracting Battalion continues to play a key role in enabling Army readiness and supporting deploying forces with timely and effective contracting solutions.
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About the MICC
Headquartered at Joint Base San Antonio-Fort Sam Houston, Texas, the Mission and Installation Contracting Command comprises about 1,500 military and civilian members who are responsible for contracting goods and services in support of Soldiers as well as readying trained contracting units for the operating force and contingency environment when called upon. A subordinate command of the Army Contracting Command and the Army Materiel Command, MICC contracts are vital in feeding more than 200,000 Soldiers every day, providing many daily base operations support services at installations, facilitate training in the preparation of more than 100,000 conventional force members annually, training more than 500,000 students each year, and maintaining more than 14.4 million acres of land and 170,000 structures.
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Original text here: https://www.army.mil/article/291546/micc_contracting_professionals_support_fort_stewart_mobilization_exercise
Lawrence Livermore National Laboratory: Cryogenic Micro-Calorimetry Offers a Novel Material-Dating Method for Nuclear Forensics and Safeguards
LIVERMORE, California, April 3 (TNSjou) -- The U.S. Department of Energy Lawrence Livermore National Laboratory issued the following news:
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Cryogenic micro-calorimetry offers a novel material-dating method for nuclear forensics and safeguards
The moment nuclear material is produced, processed or purified, it sets off a hidden countdown, marked by the half-life of its radioactive atoms as they begin to decay. For scientists tracking the origins of these substances, decoding this natural clock is crucial for verifying material histories in support of global security efforts.
In a new study
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LIVERMORE, California, April 3 (TNSjou) -- The U.S. Department of Energy Lawrence Livermore National Laboratory issued the following news:
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Cryogenic micro-calorimetry offers a novel material-dating method for nuclear forensics and safeguards
The moment nuclear material is produced, processed or purified, it sets off a hidden countdown, marked by the half-life of its radioactive atoms as they begin to decay. For scientists tracking the origins of these substances, decoding this natural clock is crucial for verifying material histories in support of global security efforts.
In a new study(https://rdcu.be/e2yKX) published in the Journal of Radioanalytical and Nuclear Chemistry, researchers at Lawrence Livermore National Laboratory (LLNL) and collaborators at the University of New Mexico and the University of Michigan offer a novel approach for measuring the age of nuclear materials. Relying on ultra-cold microcalorimeters operating at 0.01 Kelvin, the team successfully determined the age of a 100-day old plutonium sample that weighed only 26 trillionths of a gram by measuring the decay-rate ratio of plutonium-241 ((2)4(1)Pu) to its decay product americium-241 ((2)4(1)Am).
Accurate nuclear age-dating helps determine when nuclear material was made or last processed, which is important for investigating the origin of samples for nuclear forensics and safeguards. Organizations like the International Atomic Energy Agency can use these results, along with other measurements, to verify whether nuclear materials match what states have declared under international safeguards, or to identify any undeclared activities.
Traditional techniques, such as mass spectrometry, determine the age of a sample by quantifying its content of plutonium-241 and americium-241 atoms. Mass spectrometry often requires costly and time-intensive chemical separation procedures since isobaric interferences, where atoms from different elements share similar masses, can affect accuracy.
"Mass spectrometry is extremely precise, but it can require complex preparation and careful laboratory work," said Geon-Bo Kim, LLNL staff physicist. "Traditional radiation-based (radiometric) techniques, such as gamma or alpha spectrometry, are often simpler to perform, but they can become less accurate when only tiny amounts of material are available."
Gamma-ray spectrometry identifies radiation emitted by these isotopes without requiring chemical separation. However, since plutonium-241 produces notably weak gamma emissions, gamma-ray spectrometry generally demands substantially larger sample sizes than those used in this study to achieve reliable results.
Cryogenic decay energy spectrometry (DES) takes a fundamentally different approach from traditional radiation-based methods, enabling highly precise measurements even for extremely small amounts of plutonium. The method relies on one of LLNL's quantum sensing technologies, Magnetic Microcalorimetry (MMC), which has ultra-sensitive sensors cooled to near-absolute zero. When a radioactive decay happens inside the detector, it releases energy that produces an incredibly small temperature rise and a corresponding change in the material's magnetism. This change in magnetism is measured by a quantum magnetometer with extreme precision.
In the DES experiment, the team embedded the plutonium sample directly in the microcalorimeter so each decay event could be measured one by one. The ratio of the plutonium-241 and the americium-241 becomes the "radioactive clock," used to date the age of the sample with an uncertainty of only a few days.
"It's a new approach directly counting individual nuclear decays with 100% efficiency. We believe that it can complement today's state-of-the-art methods by providing an independent, orthogonal measurement for added confidence," said Kim.
DES has the potential to not only verify results but provide faster analysis and increased cost-efficiency. By eliminating the need for chemical purification that involves precise quantification of separation and recovery yields, the technique can reduce sample preparation steps and the risk of procedural errors.
These advantages position MMC and DES as a valuable tool for nuclear forensics and safeguards, enabling organizations to obtain critical information about nuclear materials more rapidly and with fewer resources.
This work was supported by the U.S. Department of Energy by Lawrence Livermore National Laboratory and funded by the National Nuclear Security Administration of the Department of Energy, Office of International Nuclear Safeguards, Office of Defense Nuclear Nonproliferation Research and Development and the Consortium for Nuclear Forensics.
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Original text here: https://www.llnl.gov/article/54221/cryogenic-micro-calorimetry-offers-novel-material-dating-method-nuclear-forensics-safeguards
Department of Justice: Trinity Hospital Agrees to Pay $1.7M to Resolve Alleged Stark Law Violations
WASHINGTON, April 3 -- The U.S. Department of Justice issued the following news release:
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Trinity Hospital Agrees to Pay $1.7M to Resolve Alleged Stark Law Violations
Trinity Hospital Holding Company (Trinity) has agreed to pay the United States $1.7 million to resolve allegations relating to improper financial relationships between Trinity and two referring physicians. Trinity operates a hospital located in Steubenville, Ohio. Trinity disclosed the arrangements at issue to the government following an independent investigation.
The Physician Self-Referral Law, commonly known as the Stark
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WASHINGTON, April 3 -- The U.S. Department of Justice issued the following news release:
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Trinity Hospital Agrees to Pay $1.7M to Resolve Alleged Stark Law Violations
Trinity Hospital Holding Company (Trinity) has agreed to pay the United States $1.7 million to resolve allegations relating to improper financial relationships between Trinity and two referring physicians. Trinity operates a hospital located in Steubenville, Ohio. Trinity disclosed the arrangements at issue to the government following an independent investigation.
The Physician Self-Referral Law, commonly known as the StarkLaw, prohibits hospitals from billing for certain services referred by physicians with whom the hospital has a financial relationship, unless that relationship satisfies one of the law's statutory or regulatory exceptions. The settlement resolves allegations that from 2014 through 2020 Trinity made improper financial contributions to two referring physicians in the form of rental arrangements for office space. The United States alleged that these arrangements violated the Stark Law because the rental arrangements exceeded fair market value.
"The Stark Law is designed to ensure that decisions about patient care are not influenced by physicians' personal financial interest," said Assistant Attorney General Brett A. Shumate of the Justice Department's Civil Division. "As this settlement reflects, we will hold accountable those who violate these important safeguards, but we will also give credit when resolving such misconduct to those who fully disclose their mistakes, take appropriate remedial actions, and meaningfully cooperate with the government's investigation."
In connection with the settlement, the United States acknowledged that Trinity took significant steps entitling it to credit for cooperating with the government. Following an internal compliance review and independent investigation, Trinity promptly took remedial action, disclosed the relevant arrangements to the government, and cooperated with the government's investigation.
The resolution obtained in this matter was the result of a coordinated effort between the Justice Department's Civil Division, Commercial Litigation Branch, Fraud Section, and the Department of Health and Human Services Office of Inspector General.
The investigation and resolution of this matter illustrates the government's emphasis on combating healthcare fraud. One of the most powerful tools in this effort is the False Claims Act. Tips and complaints from all sources about potential fraud, waste, abuse, and mismanagement can be reported to the Department of Health and Human Services at 800-HHS-TIPS (800-447-8477).
The matter was handled by Fraud Section Senior Trial Counsel David Finkelstein.
The claims resolved by the United States in the settlement are allegations only and there has been no determination of liability.
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Original text here: https://www.justice.gov/opa/pr/trinity-hospital-agrees-pay-17m-resolve-alleged-stark-law-violations
DOE Argonne National Laboratory: Can Practical Superconductors Work Without Extreme Cooling?
ARGONNE, Illinois, April 3 -- The U.S. Department of Energy Argonne National Laboratory issued the following news release:
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Can practical superconductors work without extreme cooling?
Argonne's Advanced Photon Source unlocks secrets of high-temperature superconductors
Scientists discovered how tiny changes in superhydride structure enable superconductivity at near room temperatures but extreme pressure -- offering clues for designing more practical superconductors.
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Superconductors allow electricity to flow without resistance, meaning no energy is lost as heat. This property makes them
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ARGONNE, Illinois, April 3 -- The U.S. Department of Energy Argonne National Laboratory issued the following news release:
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Can practical superconductors work without extreme cooling?
Argonne's Advanced Photon Source unlocks secrets of high-temperature superconductors
Scientists discovered how tiny changes in superhydride structure enable superconductivity at near room temperatures but extreme pressure -- offering clues for designing more practical superconductors.
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Superconductors allow electricity to flow without resistance, meaning no energy is lost as heat. This property makes themuseful for technologies such as MRI scanners, particle accelerators, magnetic-levitation trains and some power-transmission systems. Most superconductors, however, only work at extremely low temperatures -- often hundreds of degrees below zero Fahrenheit. Keeping materials that cold requires complex and costly cooling systems, which limits where the superconductors can be used.
Researchers at the U.S. Department of Energy's (DOE) Argonne National Laboratory have helped take a step toward easing that limitation. They have gained new insight into a class of materials called superhydrides that can become superconducting at much higher temperatures -- around 10 degrees Fahrenheit.
The research was carried out with collaborators from the University of Illinois Chicago (UIC), the University of Chicago and DOE's Lawrence Livermore National Laboratory. A key tool was the upgraded Advanced Photon Source (APS), a DOE Office of Science user facility at Argonne.
Superhydrides are made mostly of hydrogen, held together in an ordered structure (crystal) by a small number of metal atoms. When subjected to extremely high pressures, these materials can carry electric current with no resistance. In a landmark 2018 study, researchers led by UIC professor Russell Hemley showed that a lanthanum-based superhydride could superconduct near 8 degrees Fahrenheit. The drawback was that it only worked at pressures equivalent to those deep within the Earth (1.88 million atmospheres), making it impractical outside the lab.
In the new study, Hemley and his fellow researchers explored whether changing the material's chemistry could lower the pressure needed for superconductivity. They added a small amount of yttrium to the lanthanum superhydride to make it more stable and reduce the pressure required.
"To reach these extreme pressures, we squeezed a tiny sample between two diamonds," said Maddury Somayazulu, a physicist at the APS. The team's diamond-anvil device can generate pressures as high as five million atmospheres.
After forming the superconducting material at high pressure and temperature, the team used high-energy X-rays from the APS to study its structure (at beamlines 16-ID-B and 13-ID-D). "We focused an intense X-ray beam onto a sample only a few micrometers thick and about ten to twenty micrometers across," said Vitali Prakapenka, a beamline scientist and research professor at the University of Chicago. One micrometer is about 1/70th the width of a human hair.
The recent APS upgrade made these measurements possible. Its brighter, more tightly focused X-ray beam allowed researchers to study extremely small samples while changing the pressure. "That beam allowed us to separate signals coming from the tiny sample itself as opposed to those coming from the surrounding materials and diamond anvils," Prakapenka said.
The team found that small differences in how atoms are arranged in a crystalline lattice can strongly affect superconductivity. They identified two different crystal structures, each becoming superconducting at a slightly different temperature.
"These experiments show what the upgraded APS can do," Somayazulu said. "We can now study atomic-level structures with unprecedented detail in materials under extreme pressure."
Although the pressures used in the experiments are still very high -- about 1.4 million times atmospheric pressure -- the researchers see this as part of a longer path forward. They are adding more elements to lower the pressure further with the goal of making these materials practical.
Diamonds provide a useful comparison, Somayazulu explained. Natural diamonds form deep inside the Earth under extreme pressure and temperature. Scientists later learned how to synthesize them in the lab, and eventually how to produce them without such intense conditions. Researchers believe superhydrides could follow a similar path.
"If we understand the physics well enough, we may be able to stabilize these structures at much lower pressures but still attain superconductivity close to room temperature," Prakapenka said.
Experimental data from the APS will help guide theoretical models and AI tools in that search for new materials. Instead of testing only a few combinations at quite-challenging-to-reach extreme conditions, scientists can use AI to explore many possible multi-element compositions. They can then focus experiments on the most promising ones.
"The calculations are very demanding," Prakapenka said. "Theorists rely on high-quality experimental data to make their predictions more accurate."
Finding a material that superconducts at near room temperature and normal pressure could reshape the nation's electrical infrastructure.
The research was supported by the DOE Office of Basic Energy Sciences, DOE National Nuclear Security Administration and the National Science Foundation. Contributors include Maddury Somayazulu, Russell Hemley, Vitali Prakapenka, Abdul Haseeb Manayil-Marathamkottil, Kui Wang, Nilesh Salke, Muhtar Ahart, Alexander Mark, Rostislav Hrubiak, Stella Chariton, Dean Smith and Nenad Velisavljevic.
This article was adapted from the UIC release (https://today.uic.edu/uic-researchers-image-near-room-temperature-superconductors/).
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About the Advanced Photon Source
The U. S. Department of Energy Office of Science's Advanced Photon Source (APS) at Argonne National Laboratory is one of the world's most productive X-ray light source facilities. The APS provides high-brightness X-ray beams to a diverse community of researchers in materials science, chemistry, condensed matter physics, the life and environmental sciences, and applied research. These X-rays are ideally suited for explorations of materials and biological structures; elemental distribution; chemical, magnetic, electronic states; and a wide range of technologically important engineering systems from batteries to fuel injector sprays, all of which are the foundations of our nation's economic, technological, and physical well-being. Each year, more than 5,000 researchers use the APS to produce over 2,000 publications detailing impactful discoveries, and solve more vital biological protein structures than users of any other X-ray light source research facility. APS scientists and engineers innovate technology that is at the heart of advancing accelerator and light-source operations. This includes the insertion devices that produce extreme-brightness X-rays prized by researchers, lenses that focus the X-rays down to a few nanometers, instrumentation that maximizes the way the X-rays interact with samples being studied, and software that gathers and manages the massive quantity of data resulting from discovery research at the APS.
This research used resources of the Advanced Photon Source, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.
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Argonne National Laboratory seeks solutions to pressing national problems in science and technology by conducting leading-edge basic and applied research in virtually every scientific discipline. Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.
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The U.S. Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.
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Original text here: https://www.anl.gov/article/can-practical-superconductors-work-without-extreme-cooling
