sciencedirect: Commissioning of the neutron irradiation station at the University of Notre Dame

 

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

Volume 1075, June 2025, 170406

Full length article

Commissioning of the neutron irradiation station at the University of Notre Dame

Author links open overlay panel,

, , , , , , , ,

Department of Physics and Astronomy, University of Notre Dame, Notre Dame, IN 46556-5670, USA

Received 15 July 2024, Revised 3 March 2025, Accepted 4 March 2025, Available online 15 March 2025, Version of Record 18 March 2025.

Abstract

Cross section data for neutron-induced reactions are needed for applications in nuclear astrophysics, stockpile stewardship, and nuclear reactor design but often contain discrepancies and gaps. A neutron source with a high neutron flux, a well-characterized neutron energy distribution, and a wide range of available neutron energies is ideal for studying such reactions in order to improve on existing data and provide new experimental results. For this purpose, the Neutron Irradiation Station (NIS) was developed using the

Li(p,n)Be reaction. Neutron energy profiles were obtained using He spectrometers and neutron standards were used to determine the neutron flux using the activation method. The neutron energy profile was found to be quasi-monoenergetic and neutrons were produced at energies from 1 keV to 1 MeV. The flux at the production target was found to be (1.42+_ 0.20)*10^-8 s⁻¹cm⁻².

 

 https://doi.org/10.1016/j.nima.2025.170406

sciencedirect: Design strategy of high-entropy perovskite energy-storage ceramics: A review

 

Journal of the European Ceramic Society

Volume 44, Issue 8, July 2024, Pages 4831-4843

Design strategy of high-entropy perovskite energy-storage ceramics: A review

Author links open overlay panel,

, , , , ,

School of Materials Science and Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China

Received 3 December 2023, Revised 22 January 2024, Accepted 18 February 2024, Available online 20 February 2024, Version of Record 15 March 2024.

 

Abstract

With the increasing demand for high energy density and reliable dielectric capacitors in the field of power electronics, the research and manufacture of ceramic capacitor materials face significant challenges. At present, the traditional design ideas of dielectric ceramic materials have gradually formalized, and the system is complex and similar, whether it can design dielectric ceramic materials with high performance from a new viewpoint and explore the underlying mechanism remains a great challenge. This paper is based on ceramic capacitors with high energy storage performance, a series of high-entropy perovskite oxide ceramics designed by the concept of "entropy engineering" in the past five years are reviewed. The relationship between microstructure and macroscopic energy storage performance of materials is discussed based on the four effects of high-entropy ceramics. We predict that "entropy engineering" will be a successful strategy to break through the bottleneck of dielectric materials with high energy storage performance. This review guides the custom design of composition-structure-properties in high-entropy energy storage ceramics.

 https://doi.org/10.1016/j.jeurceramsoc.2024.02.040

Chronicles of a Trumpastrophe 5: Disease prevention programs have been cancelled and state funding for libraries and science museums has been eliminated

 

• ScienceInsider
• Health

Trump cuts damage global efforts to track diseases, prevent outbreaks

Disease surveillance programs worldwide are suddenly in limbo

• 25 Mar 2025
• 5:10 PM ET
• By Jon Cohen

 A project to track and contain menacing animal viruses across seven countries, from avian influenza in poultry to Lassa virus in rodents, ended with a single email. In late January, Jonathon Gass, an epidemiologist and virologist at Tufts University, was about to leave for Bangladesh to close out an effort to monitor and combat avian influenza, when the emailed letter arrived from the U.S. Agency for International Development (USAID), ordering an immediate halt to work on the $100 million STOP Spillover project. Gass, a co-deputy director of the project, stayed in Massachusetts and started to call staff around the world to tell them to drop everything. One colleague monitoring Lassa virus in Liberia was driving to a field site. “I had to tell him that he needed to turn the car around, come back, and book a plane ticket home,” Gass says.

 read more:  https://www.science.org/content/article/trump-cuts-damage-global-efforts-track-diseases-prevent-outbreaks

 

***

 

• ScienceInsider
• Scientific Community

Trump order could wipe out federal support for U.S. science museums

Institute of Museum and Library Services now run by Department of Labor as part of proposed dismantling

• 21 Mar 2025
• 12:40 PM ET
• By Jeffrey Mervis

 Pinedale, Wyoming, only has 2034 residents. But no town is too small for the traveling FlexCart operated by the Science Zone, a modest science museum serving residents of the most rural state in the continental United States.

read more:  https://www.science.org/content/article/trump-order-could-wipe-out-federal-support-u-s-science-museums

science.org: We started our Ph.D.s during COVID-19. Now, we’re graduating into political chaos

 

• 20 Mar 2025
• 2:00 PM ET
• By Paige Nicklas

 Five years ago, I got the email I had hoped for. “We are very pleased to offer you admission to the Neuroscience Ph.D. program,” it read, as confetti in the school’s colors rained down the screen. My parents didn’t have college degrees. I didn’t meet someone with a Ph.D. until college—and now I was going to be one, training in my first-choice program. My friend and I decided to celebrate by making some homemade mac ’n cheese, and we headed to the grocery store for milk. But there was none: The date was 13 March 2020, and COVID-19 had been declared a pandemic 2 days before. Now, I’m nearing graduation in another time of crisis—hoping to draw strength from the lessons I learned the first time around.

 read more: https://www.science.org/content/article/we-started-our-ph-d-s-during-covid-19-now-we-re-graduating-political-chaos

 

my comment:  I think that just sitting and waiting for improvement is a bad position. If there is an opportunity to find a job in a commercial company or a startup related to scientific research, then you should try to get a job there. If possible, equip your garage, as described in the article by Nature (https://www.nature.com/articles/467634a), to do home research as a hobby, or maybe for non-governmental grants, in collaboration with your university. Your own laboratory in the garage is a guarantee that your equipment and developments will not be thrown out one "fine" day. More complex research related to dangerous and licensed actions must be carried out in large scientific centers in collaboration with them.

Chronicles of a Trumpastrophe 4: Cancellation of subscriptions to scientific journals for the national library of the Department of Agriculture and reduction of funding for the fight against AIDS

 

DOGE order leads to journal cancellations by U.S. agricultural library

“We can’t do science without these,” one researcher says of the hundreds of journals no longer accessible

• 17 Mar 2025
• 5:45 PM ET
• By Jeffrey Brainard

 https://www.science.org/content/article/doge-order-leads-journal-cancellations-u-s-agricultural-library

 

 

Outgoing head of heralded U.S. global HIV/AIDS program urges Trump to reverse cuts

John Nkengasong, who had helmed PEPFAR since 2022, says “history will remember we showed humanity”

• 18 Mar 2025
• 5:45 PM ET
• By Jon Cohen

https://www.science.org/content/article/outgoing-head-heralded-u-s-global-hiv-aids-program-urges-trump-reverse-cuts

t-invariant: “If DOGE plans go through, U.S. scientific leadership will end.” American scientist – on Musk’s health care reform

 “If DOGE plans go through, U.S. scientific leadership will end.” American scientist – on Musk’s health care reform

 

In the coming days, the US Senate is expected to confirm Jay Bhattacharya as the new director of the National Institute of Health. This decision is awaited not only by the staff of the organization and scientists of the United States. The key institution of American science has been subjected to purges and pressure from the Department of Government Efficiency (DOGE), which is headed by entrepreneur and billionaire Elon Musk. Why the reforms initiated by Donald Trump’s people are reminiscent of the situation in Germany in the 1930s and how the DOGE plans threaten the development of advanced science – this was told to T-invariant on condition of anonymity by the head of one of the laboratories of the National Institute of Health.

https://t-invariant.org/2025/03/if-doge-plans-go-through-u-s-scientific-leadership-will-end-american-scientist-on-musk-s-health-care-reform/

 

sciencedirect: Influence of AC fields and electrical conduction mechanisms on the flash-onset temperature: Electronic (BiFeO3) vs. ionic conductors (8YSZ)

 

Ceramics International

Volume 49, Issue 9, Part B, 1 May 2023, Pages 14834-14843

Influence of AC fields and electrical conduction mechanisms on the flash-onset temperature: Electronic (BiFeO₃) vs. ionic conductors (8YSZ)

Sandra Molina-Molina a, Antonio Perej´on a,b,**, Luis A. P´erez-Maqueda a,***, Pedro E. S´anchez-Jim´enez a,b,*

^a

Instituto de Ciencia de Materiales de Sevilla, Consejo Superior de Investigaciones Científicas-Universidad de Sevilla, Calle Américo Vespucio 49, Sevilla, 41092, Spain

^b

Departamento de Química Inorgánica, Facultad de Química, Universidad de Sevilla, Sevilla, 41012, Spain

Received 27 February 2022, Revised 21 June 2022, Accepted 22 June 2022, Available online 1 July 2022, Version of Record 22 March 2023.

 

Abstract

This work aims to clarify the influence of AC (up to 50 kHz) vs DC fields on the flash-onset temperature, emphasizing the role of the electrical conduction mechanism. BiFeO₃ (BFO) is used as an example of electronic conductor while 8-mol % Yttria-stabilized zirconia (8YSZ) is used as an example of ionic conductor. For 8YSZ, a frequency dependence of the flash-onset temperature and flash-induced heating is observed. This is consistent with the different contributions found in the total electrical response of 8YSZ as characterized by impedance spectroscopy measurements. Estimations based on the blackbody radiation model suggest that 8YSZ samples attain higher temperatures under AC fields due to a more efficient heating. Moreover, a noticeable decrease in the activation energy for the electrical conduction after the flash is triggered is attributed to electronic conduction. Meanwhile, the lack of frequency response and insensitiveness to the type of electrical field found in the case of BFO can be attributed to its mainly electronic bulk conduction.

 

https://www.sciencedirect.com/science/article/pii/S0272884222022763

sciencedirect: Flash sintering improves magnetic properties of spinel zinc ferrite

 

Scripta Materialia

Volume 236, November 2023, 115681

Flash sintering improves magnetic properties of spinel zinc ferrite

Soumyadeep Sur, Parmanand Kumar Tyagi, Shikhar Krishn Jha

Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India

Received 11 June 2023, Revised 20 July 2023, Accepted 22 July 2023, Available online 28 July 2023, Version of Record 28 July 2023.

 

Abstract

We report on a simple protocol for one step synthesis and sintering of single-phase magnetic spinel ZnFe₂O₄ zinc ferrite (ZFO) using an electric field assisted sintering. The resultant materials show improved saturation magnetization and higher coercivity compared to conventionally sintered ferrite. The changes in properties have been attributed to generation of non-thermal lattice defects when processed under electric field. Instead of using the high temperatures (>1000 °C) and extended dwell periods (> 4 h) required by the traditional sintering processes, this method permits sintering of ZFO at a furnace temperature of only 950 °C in just a minute by applying a minimal field of 25 Vcm⁻¹. This magnetic material with decreased coercivity and increased saturation magnetization will improve the efficiency of solenoids, transformer/inductor cores, microwave devices and magnetic shields.

 

https://www.sciencedirect.com/science/article/pii/S1359646223004049

Chronicles of a Trumpastrophe 3: Sticker shock: New U.S. tariffs could raise cost of research equipment and supplies

 

• ScienceInsider
• Science and Policy

Sticker shock: New U.S. tariffs could raise cost of research equipment and supplies

China, Canada, and Mexico are major suppliers of essential scientific items

• 4 Mar 2025
• 4:40 PM ET
• By Catherine Offord

The tariffs imposed today by the United States on its three largest trading partners could not only drive up the cost of goods for U.S. consumers, but also hit researchers by raising prices for scientific equipment.

read more:  https://www.science.org/content/article/sticker-shock-new-u-s-tariffs-could-raise-cost-research-equipment-and-supplies

Chronicles of a Trumpastrophe 2

 1. Trump Tracker. Recent: What happened to FDA’s meeting to pick the next seasonal flu vaccine?    28 Feb 2025 By Science News Staff

 https://www.science.org/content/article/science-trump-latest-news

2.  Trump credit card freeze sparks alarm at health agencies. “Cost efficiency” order could block travel, supplies for labs and patient care.  27 Feb 20256:00 PM ET By Meredith Wadman, Jocelyn Kaiser

https://www.science.org/content/article/trump-credit-card-freeze-sparks-alarm-health-agencies

Science: First petawatt electron beam arrives, ready to rip apart matter and space

 

• News
• Physics

First petawatt electron beam arrives, ready to rip apart matter and space

Ultra–high-power particle pulses could boost x-ray science and laboratory astrophysics

• 27 Feb 2025
• 5:05 PM ET
• By Adrian Cho

read more: https://www.science.org/content/article/first-petawatt-electron-beam-arrives-ready-rip-apart-matter-and-space 

 ***

 

My comment: This is a surprising thing for me, although the physics is very clear. This is the ability to cause nuclear reactions with subthreshold (essentially optical, non-nuclear) electromagnetic radiation. Only due to the high intensity of light, and therefore high voltages of the electrical component.

sciencedirect: Flash sintering of complex shapes

Applied Materials Today
Volume 26, March 2022, 101293

Flash sintering of complex shapes

Charles Manière a b 1 2, Geuntak Lee a 1, Eugene A. Olevsky a 1

a    Powder Technology Laboratory, San Diego State University, San Diego, United States of America

b    Normandie Univ, ENSICAEN, UNICAEN, CNRS, CRISMAT, Caen, France

Received 1 September 2021, Revised 16 November 2021, Accepted 24 November 2021, Available online 7 December 2021, Version of Record 7 December 2021.

 

Highlights

• •
  Flash spark plasma sintering scalability.
• •
  Interface method for spark plasma complex shaping.
• •
  Flash sintering of complex shapes.

Abstract

Flash (ultra-rapid) sintering of powder materials is a Multiphysics phenomenon which has a potential for the quasi-instantaneous fabrication of various components. However, the intrinsic instability of flash sintering makes it difficult to apply to complex shapes and large specimens. Here, we circumvent this problem by the use of an interface-controlled approach to impose stable and very fast heating to large powder samples which become fully dense in a matter of seconds. The Multiphysics simulation demonstrated that an electric-thermal-mechanical confinement of the specimen allows a very efficient (and selective) heating and sintering of the powder specimen with a homogeneous microstructure and a substantial reduction of the grain growth. Our results indicate that the ultra-rapid sintering of large and complex shape samples is possible.

 https://www.sciencedirect.com/science/article/pii/S2352940721003565

Chronicles of a Trumpastrophe: Mass firings decimate U.S. science agencies

 science

Mass firings decimate U.S. science agencies

White House dismissals and rationale challenged by dismissed scientists and lawsuits

• 18 Feb 2025
• 5:55 PM ET
• By John Travis, Katie Langin, Jocelyn Kaiser, Meredith Wadman

 On 13 February, a research entomologist at the U.S. Department of Agriculture (USDA) was among the first, receiving an email after the close of business hours saying they were being “removed” from what they describe as a dream job, studying a key problem in agriculture science. The change had gone into effect 14 minutes before the email arrived. “The letter said I was being let go due to poor performance, which is nonsensical since they invited me to apply for a promotion just the other month,” the stunned researcher says.

read more:  https://www.science.org/content/article/mass-firings-decimate-u-s-science-agencies

sciencedirect: A novel Multi‐Phase Flash Sintering (MPFS) technique for 3D complex‐shaped ceramics

 Applied Materials Today 26 (2022) 101274

A novel Multi-Phase Flash Sintering (MPFS) technique for 3D complex-shaped ceramics

Sandra Molina-Molina a,1, Eva Gil-González a,b,1,∗, Francisco José Durán-Olivencia c,
José Manuel Valverde d, Antonio Perejón a,e, Pedro E. Sánchez-Jiménez a,e,∗,
Luis A. Pérez-Maqueda a,∗

Highlights

• •
  First demonstration of enhanced flash sintering by a rotating electric field.
• •
  Larger power densities allow for reduced sintering temperatures.
• •
  A wide variety of ceramics can be more efficiently sintered by MPFS.
• •
  Homogeneous sintering is attainable even for complex-shaped specimens.

Abstract

This work demonstrates the first proof-of-concept of Multi-Phase Flash Sintering (MPFS). This novel technique essentially consists of applying a rotating electric field to the sample by means of a multi-phase voltage source as furnace temperature increases. Several ceramic materials with different types of electrical conductivities are sintered within seconds at furnace temperatures much lower than those used for traditional DC flash sintering due to the higher power densities administered by a multi-phase power supply. Thus, ceramic materials are flashed at relatively lower applied voltages which minimizes undesired phenomena such as localization and preferential current pathways. Furthermore, MPFS allows diverse electrode configurations to promote a more uniform electric field distribution, enhancing the sintering of 3D complex-shaped specimens. MPFS could be a true breakthrough in materials processing, as 3D complex-shaped specimens are homogeneously sintered at reduced temperatures, while keeping all the advantages of conventional flash sintering.

https://www.sciencedirect.com/science/article/pii/S2352940721003371

science: Trump Tracker

 

Trump Tracker

Latest on firings: Protest outside HHS headquarters

• 18 Feb 2025
• By Science News Staff

Recent Trackers: NSF’s firing maneuver | HHS protest | Indirect costs for dummies
Story tips, internal Trump administration or science agency emails, or other key documents?  Contact us. 

---

19 Feb 2025, 6:10 PM ET

‘Brazen defiance.’ Are Trump officials obeying an order to unfreeze foreign aid?

President Donald Trump’s administration says it is within its rights to continue an extensive freeze on foreign aid, despite being told to lift the blockade by a federal judge. But administration opponents say that claim is “brazen defiance” of the judge’s order.

Read more: https://www.science.org/content/article/science-trump-latest-news

Ceramics International: Expanding the scope of multiphase-flash sintering: Multi-dogbone configurations and reactive processes

 

Ceramics International

Volume 50, Issue 14, 15 July 2024, Pages 25210-25215

 

 

Expanding the scope of multiphase-flash sintering: Multi-dogbone configurations and reactive processes

A.F. Manchón-Gordón a
, S. Molina-Molina a, A. Perejón a b, A. Alcalde-Conejo a, P.E. Sánchez-Jiménez a b, L.A. Pérez-Maqueda a

a
    Instituto de Ciencia de Materiales de Sevilla, ICMSE CSIC-Universidad de Sevilla, C. Américo Vespucio 49, Sevilla, 41092, Spain

b
    Departamento de Química Inorgánica, Facultad de Química, Universidad de Sevilla, 41012, Sevilla, Spain

Received 1 March 2024, Revised 5 April 2024, Accepted 19 April 2024, Available online 20 April 2024, Version of Record 3 June 2024.

 

Abstract

In this work, we have expanded the possibilities of the multiphase-flash sintering (MPFS) technique by investigating several configurations that involve multiple dogbone specimens (ranging from 1 to 3) and multiple phases (also ranging from 1 to 3). Unlike the traditional MPFS approach using complex 3D or cylindrical samples, this new method allows for a direct comparison with the established conventional flash sintering technique. Our experimental results with dense 8-mol% Yttria-stabilized zirconia demonstrate a significant reduction in the onset temperature as the number of phases and dogbones increases. Building on these findings, we achieved the preparation of pure bulk specimens of SrFe₁₂O₁₉ for the first time through reactive multiphase-flash sintering.

 

https://www.sciencedirect.com/science/article/pii/S027288422401647X

 

Vacuum: Investigation of intense pulsed ion beam generation by a magnetically insulated ion diode at a reduced impedance

 

Vacuum

Volume 217, November 2023, 112496

 

Investigation of intense pulsed ion beam generation by a magnetically insulated ion diode at a reduced impedance

Marat Kaikanov, Dosbol Nauruzbayev, Alshyn Abduvalov, Kanat Baigarin

    Nazarbayev University, Astana, 010000, Kazakhstan

Received 22 March 2023, Revised 9 August 2023, Accepted 10 August 2023, Available online 11 August 2023, Version of Record 14 August 2023.

 

Abstract

The intense pulsed ion beam (IPIB) generation was investigated at reduced impedance of a magnetically insulated ion diode. The main goal of our research was to obtain IPIB with adjustable parameters at low current densities. The diode impedance was varied by the external magnetic field current by setting the delay of the accelerator's trigger relative to the launch of the magnetic field generator. The B-applied ion diode adjustably generated IPIB with a current density in the range from 25 to 4 A/cm². In the matched mode the accelerator generates the ion beam with a current density of about 100 A/cm². Obtained results of the IPIB current density adjustment allows to irradiate samples in a single vacuum cycle without the change of charging voltage of both magnetic field and accelerating voltage generators. Gold films with a thickness of 10 nm deposited on fluorine-doped tin oxide (FTO)/glass substrates were irradiated to demonstrate the applicability of obtained IPIB for irradiation of thin coatings without their deterioration. Single shot of IPIB with current density of 20 A/cm² transformed Au film to spherical micro-particles, while after irradiation at the same fluence with 5 pulses of IPIB with current density of 4 A/cm² Au coating was preserved as a film.

 

 https://www.sciencedirect.com/science/article/pii/S0042207X23006930

Ceramics International: Influence of the atmosphere on the formation of high-entropy oxides within the Co–Cu–Fe–Mg–Mn–Ni–O system via reactive flash sintering

 

Ceramics International

Volume 50, Issue 21, Part B, 1 November 2024, Pages 42276-42285

 

Influence of the atmosphere on the formation of high-entropy oxides within the Co–Cu–Fe–Mg–Mn–Ni–O system via reactive flash sintering

 A.F. Manchón-Gordón a, C. Lobo-Llamas a, S. Molina-Molina a, A. Perejón a b
, P.E. Sánchez-Jiménez a, L.A. Pérez-Maqueda a

a
    Instituto de Ciencia de Materiales de Sevilla, ICMSE CSIC-Universidad de Sevilla, C. Américo Vespucio 49, Sevilla, 41092, Spain

b
    Departamento de Química Inorgánica, Facultad de Química, Universidad de Sevilla, Sevilla, 41012, Spain

Received 8 May 2024, Revised 22 July 2024, Accepted 4 August 2024, Available online 5 August 2024, Version of Record 27 September 2024.

 

Abstract

In this study, the feasibility of preparing quinary equimolar high-entropy oxides within the Co–Cu–Fe–Mg–Mn–Ni–O system was explored using the reactive flash sintering (RFS) technique. Various compositions were tested using this technique under atmosphere pressure, leading to the formation of two primary phases: rock-salt and spinel. Conversely, a new high-entropy oxide was produced as a single-phase material with the composition (Co_0.2,Cu_0.2,Mg_0.2,Mn_0.2,Ni_0.2)O when RFS experiments were conducted in nitrogen atmosphere. The reducing conditions achieved in nitrogen enabled the incorporation of cations with oxidation states different from +2 into the rock-salt lattice, emphasizing the critical role of the processing atmosphere, whether inert or oxidizing, in the formation of high-entropy oxides. The electrical characterization of this material was obtained via impedance spectroscopy, exhibiting a homogeneous response attributed to electronic conduction with a temperature dependence characteristic of disordered systems.

 

https://www.sciencedirect.com/science/article/pii/S0272884224035028

ScienceAdvances: Electric plasma guided with ultrasonic fields

 

Electric plasma guided with ultrasonic fields

Josu Irisarri, Iñigo Ezcurdia, Naroa Iriarte, Marika Sirkka, Dmitry Nikolaev h, Joni Mäkinen, Alexander Martinez-Marchese, Denys Iablonskyi, Ari Salmi, and Asier Marzo

Science Advances

5 Feb 2025

Vol 11, Issue 6

 

Electric plasma forms sparks in midair that transfer electrical current. This current can power high-voltage electronics, kill bacteria, produce tactile sensations, or be used for welding. However, the formation of the spark is chaotic and hard to control. Laser pulses can guide discharges but require high power and are disruptive and cumbersome to control. Here, we show that ultrasonic fields can guide plasma sparks, even around obstacles. The ultrasonic beams can be directed dynamically and within milliseconds, enabling precise, nondangerous, and fast control of high-voltage sparks. This phenomenon can be used for applications in high-voltage switching and plasma treatments.

 

https://www.science.org/doi/10.1126/sciadv.adp0686

ScienceAdvances: 187Os nuclear resonance scattering to explore hyperfine interactions and lattice dynamics for biological applications

¹⁸⁷Os nuclear resonance scattering to explore hyperfine interactions and lattice dynamics for biological applications

Iryna Stepanenko, Zhishuo Huang , Liviu Ungur , Dimitrios Bessas, Aleksandr Chumakov, Ilya Sergueev, Gabriel E. Büchel, Abdullah A. Al-Kahtani, Liviu F. Chibotaru , Joshua Telser , and Vladimir B. Arion

Science Advances

7 Feb 2025

Vol 11, Issue 6

Abstract

Osmium complexes with osmium in different oxidation states (II, III, IV, and VI) have been reported to exhibit antiproliferative activity in cancer cell lines. Herein, we demonstrate unexplored opportunities offered by ¹⁸⁷Os nuclear forward scattering (NFS) and nuclear inelastic scattering (NIS) of synchrotron radiation for characterization of hyperfine interactions and lattice dynamics in a benchmark Os(VI) complex, K₂[OsO₂(OH)₄]. We determined the isomer shift [δ = 3.3(1) millimeters per second] relative to [Os^IVCl₆]²⁻ and quadrupole splitting [ΔE_Q = 12.0(2) millimeters per second] with NFS. We estimated the Lamb-Mössbauer factor [0.80(4)], extracted the density of phonon states, and carried out a thermodynamics characterization using the NIS data combined with first-principles calculations. Overall, we provide evidence that ¹⁸⁷Os nuclear resonance scattering is a reliable technique for the investigation of hyperfine interactions and Os-specific vibrations in osmium(VI) species and is thus applicable for such measurements in osmium complexes of other oxidation states, including those with anticancer activity such as Os(III) and Os(IV).

 

 https://www.science.org/doi/10.1126/sciadv.ads3406