We are a materials chemistry group studying novel synthesis routes under extreme compression. We use cutting-edge techniques to subject samples to pressures on the order of millions of atmospheres, allowing us to access exotic states of matter and synthesize previously undiscovered solid-state compounds. We also use first-principles calculations to explore high-pressure phase space in silico, and to study the bulk properties of newly discovered phases.
High pressure represents a vastly unexplored phase space where novel compounds can be synthesized and recovered back to ambient conditions. We use experimental high-pressure synthesis techniques to discover completely new solid-state compounds that could underpin future advances in technology.
Modern first-principles methods can be used to accurately calculate the formation enthalpy of any given structure. We use random structure searching tools to perform high-throughput DFT calculations in search of undiscovered high-pressure phases. We also use machine learning methods to investigate how pressure can influence chemical disorder in the solid state.
Shockwaves subject materials to very high pressures over extremely short timescales, potentially offering a route toward the kinetic control of solid-state transformations. We use cutting-edge in situ X-ray diffraction methods to examine phase transformations under dynamic compression.
Systems that exhibit magnetic frustration are a direct route to exotic new states of matter dominated by quantum fluctuations. Control over these delicate quantum states is an outstanding challenge in chemistry and physics. We are using high pressures to target novel quantum phases in geometrically frustrated systems.
Dr. James Walsh
Assistant Professor
Postdoctoral Fellow, Northwestern
MChem, Ph.D., University of Manchester, UK
Anshu Baiya
First Year Graduate Student
M.Sc., Indian Institute of Technology (BHU), 2023
Chloe Miller
Undergraduate Student
B.A., Mount Holyoke College (expected 2028)
Zeynep Alptekin
Undergraduate Student (2020–2024)
B.Sc., UMass Amherst, 2024
Now: Grad Student at Northwestern.
Nick Manganaro
Graduate Student (2019–2024)
B.Sc., University of New Haven, 2019
Ph.D., UMass Amherst, 2024
Now: Lecturer at Bates College.
Paul Marshall
Graduate Student (2019–2024)
B.S., Wayne State University, 2019
Ph.D., UMass Amherst, 2024
Now: Postdoc at Texas A&M.
Wyatt Mitchell
Undergraduate Student (2020–2024)
B.Sc., UMass Amherst, 2024
Now: Grad Student at Michigan State.
Kim Pereira
Graduate Student (2019–2024)
B.Sc., Union College, 2017
Ph.D., UMass Amherst, 2024
Now: Senior Laser Product Engineer at Coherent.
Scott Thiel
Graduate Student (2019–2024)
B.Sc., Rensselaer Polytechnic Institute, 2019
Ph.D., UMass Amherst, 2024
Now: Postdoc at Duke.
High-pressure synthesis of martensite-type ε-VCy″
Cote, E. E.; Nelson, T. L.; Ambos, S. D.; Arigbede, J.; Walsh, C.; Brooks H. L.; Whitaker, M. L.; Walsh, J. P. S.
Submitted.
Stability of the fcc phase in shocked nickel up to 332 GPa
Pereira, K. A.; Clarke, S. M.; Singh, S; Briggs, R.; McGuire, C. P.; Lee, H. J.; Khaghani, D.; Nagler, B.; Galtier, E.; Cunningham, E.; McGonegle, D.; Tracy, S. J.; Vennari, C.; Gorman, M. G.; Coleman, A. L.; Davis, C.; Hutchinson, T.; Eggert, J. H.; Smith, R. F.; Walsh, J. P. S.
Nat. Commun. 2025, 16, 4385. [PDF]
Fragmenting the kagomé lattice: Pressure-tuned anisotropy of Cu2+ triangles in a novel atacamite relative, CaCu(OH)3Cl
Ambos, S. D.; Manganaro, N. S.; DeCapua, M.; Zhang, D.; Nguyen, P.; Yan, J.; Walsh, J. P. S.
J. Phys. Chem. C 2024, 129, 4226–4232. [PDF] [Front Cover]
High-pressure synthesis and recovery of single crystals of the metastable manganese carbide, MnCx
Marshall, P. V.; Thiel, S. D.; Cote, E. E.; Arigbede, J.; Whitaker, M. L.; Walsh, J. P. S.
Chem. - Eur. J. 2024, 30, e202401581. [PDF]
High-pressure polymorphism in silver ferrite delafossite, AgFeO2
Manganaro, N. S.; Ambos, S. D.; DeCapua, M.; Thiel S. D., Mitchell, W. E.; Liu, Z.; Zhang, D.; Nguyen, P. Q. H.; Lavina, B.; Alp, E. E.; Yan, J.; Walsh, J. P. S.
Inorg. Chem. 2024, 63, 9763–9770. [PDF]
Combined first-principles and experimental investigation into the reactivity of co-deposited chromium–carbon samples under pressure
Marshall, P. V.; Thiel, S. D.; Cote, E. E.; Hrubiak, R.; Whitaker, M. L.; Meng, Y.; Walsh, J. P. S.
ACS Mater. Au 2024, 63, 9763–9770. [PDF] [Front Cover]
First-principles investigation of phase stability in substoichiometric zirconium carbide under high pressure
Thiel, S. D.; Walsh, J. P. S.
Adv. Theory Simul. 2022, 5, 2200439. [PDF] [Front Cover]
X-ray diffraction methods for high-pressure solid-state synthesis (Book Chapter)
Thiel, S. D.; Tamerius, A. D.; Walsh, J. P. S.
Compr. Inorg. Chem. III 2022, 200–221.
High-pressure synthesis of bulk cobalt cementite, Co3C
Marshall, P. V.; Alptekin, Z.; Thiel, S. D.; Smith, D.; Meng, Y.; Walsh, J. P. S.
Chem. Mater. 2021, 33, 9601–9607. [PDF] [Front Cover]
High-pressure chemistry
Walsh, J. P. S.
Commun. Chem., 2025, 8, 168 [PDF]
Shock compression experiments using the DiPOLE 100-X laser on the high energy density instrument at the European X-ray free electron laser: Quantitative structural analysis of liquid Sn
Gorman, M. G.; [...] Pereira, K. A.; [...] Walsh, J. P. S.; [...] McMahon, M. I.
J. Appl. Phys., 2024, 135, 165902 [PDF]
Designing magnetic properties in CrSBr through hydrostatic pressure and ligand substitution
Telford, E. J.; Chica, D. G.; Ziebel, M. E.; Xie, K; Manganaro, N. S.; Huang, C.-Y.; Cox, J.; Dismukes, A. H.; Zhu, X.; Walsh, J. P. S.; Cao, T.; Dean, C. R.; Roy X.
Adv. Physics Res., 2023, 2, 2300036. [PDF]
"Pink"-beam X-ray powder diffraction profile and its use in Rietveld refinement
Von Dreele, R.; Clarke S. M.; Walsh, J. P. S.
J. Appl. Cryst., 2021, 54, 3–6. [PDF]
Anisotropic structural collapse of Mg3Sb2 and Mg3Bi2 at high pressure
Calderón-Cueva, M.; Peng, W.; Clarke S. M.; Ding, J.; Brugman, B. L.; Levental, G.; Balodhi, A.; Rylko, M.; Delaire, O.; Walsh, J. P. S.; Dorfman, S. M.; Zevalkink, A.
Chem. Mater., 2021, 33, 567–573. [PDF]
Computationally directed discovery of MoBi2
Altman, A. B.; Tamerius, A. D.; Koocher, N. Z.; Meng, Y.; Pickard, C.; Walsh, J. P. S.; Rondinelli, J. M.; Jacobsen, S. D.; Freedman, D. E.
J. Am. Chem. Soc. 2021, 143, 214–222. [PDF]
Pressure induced collapse of magnetic order in jarosite
Klein, R. A.; Walsh, J. P. S.; Clarke S. M.; Liu, Z.; Alp, E. E.; Bi, W.; Meng, Y.; Altman, A. B.; Chow, P.; Xiao, Y.; Norman, M. R.; Rondinelli, J. M.; Jacobsen, S. D.; Puggioni, D.; Freedman, D. E.
Phys. Rev. Lett. 2020, 125, 077202. [PDF]
High-pressure synthesis of the BiVO3 perovskite
Klein, R. A.; Altman, A. B.; Saballos, R. J.; Walsh, J. P. S.; Tamerius, A. D.; Meng, Y.; Puggioni, D.; Jacobsen, S. D.; Rondinelli, J. M.; Freedman, D. E.
Phys. Rev. Mater. 2019, 3, 64411. [PDF]
MnBi2: A metastable high-pressure phase in the Mn–Bi system
Walsh, J. P. S.; Clarke S. M.; Puggioni, D.; Tamerius, A. D.; Meng, Y.; Rondinelli, J. M.; Jacobsen, S. D.; Freedman, D. E.
Chem. Mater. 2019, 31, 3083–3088. [PDF]
Controlling dimensionality in the Ni–Bi system with pressure
Clarke S. M.; Powderly, K. M.; Walsh, J. P. S.; Yu, T.; Wang, Y.; Meng; Y.; Jacobsen, S. D.; Freedman, D. E.
Chem. Mater. 2019, 31, 955–959. [PDF]
Discovery of Cu3Pb
Tamerius, A. D.; Clarke S. M.; Gu, M.; Walsh, J. P. S.; Esters, M.; Meng, Y.; Hendon, C. H.; Rondinelli, J. M.; Jacobsen, S. D.; Freedman, D. E.
Angew. Chem. Int. Ed. 2018, 57, 12809–12813. [PDF]
Impact of pressure on magnetic order in jarosite
Klein, R. A.; Walsh, J. P. S; Clarke S. M.; Guo, Y.; Bi, W.; Fabbris, G.; Meng, Y.; Haskel, D.; Alp, E. E.; Van Duyne, R. P.; Jacobsen, S. D.; Freedman, D. E.
J. Am. Chem. Soc. 2018, 140, 12001–12009. [PDF] [Front Cover]
High-pressure synthesis: A new frontier in the search for next-generation intermetallic compounds
Walsh, J. P. S.; Freedman, D. E.
Acc. Chem. Res. 2018, 51, 1315–1323. [PDF]
Creating binary Cu–Bi compounds via high-pressure synthesis: A combined experimental and theoretical study
Clarke S. M.; Amsler, M.; Walsh, J. P. S.; Yu, T.; Wang, Y.; Meng, Y.; Jacobsen, S. D.; Wolverton, C.; Freedman, D. E.
Chem. Mater. 2017, 29, 5276–5285. [PDF]
Discovery of FeBi2
Walsh, J. P. S.; Clarke S. M.; Meng, Y.; Jacobsen, S. D.; Freedman, D. E.
ACS Cent. Sci. 2016, 2, 867–871. [PDF]
Discovery of a superconducting Cu–Bi intermetallic compound by high-pressure synthesis
Clarke, S. M.; Walsh, J. P. S.; Amsler, M.; Malliakas, C. D.; Yu, T.; Goedecker, S.; Wang, Y.; Wolverton, C.; Freedman, D. E.
Angew. Chem. Int. Ed. 2016, 55, 13446–13449. [PDF]
We are delighted to welcome Anshu Anshu to the Walsh Lab! Anshu earned her chemistry degree at the Indian Institute of Technology Varanasi. She will now help to drive forward our experimental high-pressure materials discovery program.
Liz and Tracey return to the NSLS-II for more Multi-anvil Press experiments. Tracey helped to improve the beamline operations and experimental team morale. Leroy Sharkington, the new mascot of MAXPD, is seen below being assisted to his new home by Tracey. Thank you to Matt Whitaker for his support carrying out these experiments! [Photo]
Liz and Tracey were able to successfully complete DAC experiments with the newly updated beam at Beamline 16-ID-B! Thank you to Ross Hrubiak and Dean Smith for their assistance for Tracey and Liz’s first visit to the APS! [Photo]
Liz Cote and Tracey Nelson each won poster prizes at ResearchFest 2024. Liz won the Marvin D. Rausch Lectureship Award for Outstanding Poster Presentation while Tracey won the Dr. Paul Hatheway Terry Endowment Award for Outstanding Poster. Congratulations, both! [Photo]
Kim successfully defended her Ph.D. thesis, “Exploring the phase transitions of materials using femtosecond X-ray diffraction under dynamic compression.” She will join Coherent Corp. as a Senior Laser Product Engineer. Congratulations, Kim! [Photo]
Nick successfully defended his Ph.D. thesis, “Polymorphism in Silver Delafossites Under Extreme Pressures.” He will join Bates College as a lecturer in the chemistry department this fall. Congratulations, Nick! [Photo]
Scott successfully defended his Ph.D. thesis, “On the Non-Stoichiometry and Phase Stability of Transition Metal Carbides Under High Pressures.” He will join Stefano Curtarolo's group at Duke as a postdoc this fall. Congratulations, Scott! [Photo]
Paul successfully defended his Ph.D. thesis, “Materials Discovery at Extreme Conditions.” He will join Alison Altman's group at Texas A&M as a postdoc this fall. Congratulations, Paul! [Photo]
Liz and Tracey ran their first laser-heated DAC experiment at the 12.2.2 beamline at the Advanced Light Source in Berkeley, CA. Thank you to Kat Armstrong for helping us navigate our first beamtime at the ALS! [Photo]
Zeynep Alptekin has accepted an offer to join the materials science and engineering graduate program at Northwestern University, starting in Fall 2024. Congratulations, Zeynep!
Wyatt Mitchell has accepted an offer to join the chemistry graduate program at Michigan State University, starting in Fall 2024. Congratulations, Wyatt! And Go Green!
John Arigbede, Liz Cote, and Tracey Nelson visited the large volume press at the NSLS-II 28-ID-2 beamline to carry out more high-pressure syntheses of transition metal carbides. Thank you to Matt Whitaker for making John and Tracey's first visit a success! [Photo]
We are thrilled to welcome Tracey Nelson to the Walsh Lab! Tracey earned her chemistry degree at St. Olaf College in Minnesota, where she worked in the lab of Prof. Elodie Marlier studying novel catalysts based on tetradentate N2P2 ligands.
Kim performed shockwave experiments across two systems on the Matter in Extreme Conditions Instrument at the LCLS in the SLAC National Accelerator Laboratory in California. Thank you to the Livermore team for making these experiments possible! [Photo]
Nick Manganaro has started teaching his First Year Seminar course on game theory. This is a course that Nick designed from scratch as part of his CNS Teaching Fellowship. Good luck, Nick!
The Directed Energy Professional Society has awarded Kim a $10,000 research grant to support her collaborative work with LLNL on laser shock compression. Congratulations, Kim!
Work performed in collaboration with the Roy Research Group studying CrSBr under pressure was published in Advanced Physics Research. Check it out here!
James visited Lawrence Livermore National Laboratory in California to deliver a seminar in the Materials Science Division. While there, he caught up with Kim and Zeynep, who are both interning at the lab over the summer and doing great science!
After passing his ChemE qualifying exam with flying colors, John Arigbede is now officially a PhD candidate in the Walsh Lab! He will work on studying our newly discovered electron-rich transition metal carbides as heterogeneous catalysts.
The Walsh Lab has been awarded a grant from the American Chemical Society Petroleum Research Fund to study our novel transition metal carbides as heterogeneous catalysts! We are very grateful to the Petroleum Research Fund for their support.
The Walsh Lab was well represented at the Chemistry Department Awards Dinner, with Wyatt receiving the John A. Chandler Memorial Scholarship and Zeynep taking home the ACS Division of Inorganic Chemistry Undergraduate Award. Well done to both!
Nick and Scott traveled to the Advanced Photon Source to learn how to work up synchrotron Mössbauer data during an intensive three-day workshop. Thank you to the organizers for putting on a fantastic workshop!
Liz Cote, Scott Thiel, and Paul Marshall carried out some high-pressure synthesis reactions on the large volume press at beamline 28-ID-2 at the NSLS-II. Thank you to Matt Whitaker for being a fantastic host! [Photo]
Scott Ambos and Nick Manganaro were back at the APS to collect some high-pressure single crystal diffraction data. Thank you as always to Dongzhou Zhang and Phuong Nguyen for their support. [Photo]
Kim will be spending the summer as a High Energy Density Science Center (HEDS) Grad Student at Lawrence Livermore National Laboratory. She will participate in experiments across Omega, MEC, JLF, and DiPOLE. [Photo]
The DOE Science Undergraduate Laboratory Internships (SULI) program will support Zeynep for a summer internship at Lawrence Livermore National Laboratory, where she will help to prepare and study a new class of thermal barrier coatings.
Nick Manganaro and Scott Ambos spent four days collecting high-pressure synchrotron Mössbauer at Sector 3 of the APS. Thank you to Barbara Lavina and Ercan Alp for helping us collect some great data! [Photo]
We are excited to welcome Liz Cote to the Walsh Lab! Liz joins us from the University of New Haven, where she worked with the group of Prof. Dequan Xiao on the design of molecular catalysts for polymer degradations.
The Walsh Lab has been awarded an NSF CAREER grant to fund our work on the development of novel methods for high-pressure synthesis! We are very grateful to the Division of Materials Research for their support.
Kim was the recipient of not one but two chemistry graduate fellowships awarded through the department. She received both the Donald Kuhn Graduate Fellowship Award and the PPG Fellowship. Congratulations, Kim!
Paul Marshall and Scott Thiel set sail for Long Island to perform large volume press synthesis experiments at beamline 28-ID-2 of the NSLS-II. Here is a photograph of the Lab's first Kawai assembly. Thank you to Matt Whitaker for making the experiments a success!
Nick Manganaro and Scott Ambos visited the Partnership for Extreme Crystallography beamline at the Advanced Photon Source in Chicago to perform high-pressure X-ray crystallography experiments. Thank you to Dongzhou Zhang and Phuong Nguyen for training and assistance!. [Photo]
Kim won a first-place award for her poster presentation at the UMass Chemistry Department's ResearchFest 2022. Here she is receiving her award certificate from department head Rick Metz. [Photo]
Scott's paper reporting on the use of cluster expansion to study the effect of pressure on vacancies in zirconium carbide has been published in Advanced Theory and Simulations. Nice work, Scott!
Kim was back at the Advanced Photon Source to perform experiments at the Dynamic Compression Sector. Thank you to the excellent support team for making the experiments a success!
Kim won an award for her poster presentation of her shockwave work at the 2022 Research at High Pressure GRC. Her prize was a copy of Sergei Stishov's book The ABCs of High Pressure. [Photo]
Wyatt was awarded the Roger G. Bates Fund to support his research in our lab over the summer. He will continue his work on the high-pressure synthesis of novel carbides. [Photo]
Kim Bolduc, Nick Manganaro, and Scott Thiel each won the Chemistry Department Ambassador Award!
Zeynep was awarded the 2021–2022 UMass Rising Researcher Award for her outstanding achievements in research! Click here to read more about her award. [Photo]
Zeynep was awarded the Uche Anyanwu Memorial Award for her poster presentation at the Chemistry Undergraduate Poster Session. She presented her work on the high-pressure bulk synthesis of cobalt cementite using the laser-heated diamond anvil cell. [Photo]
Zeynep was awarded the prestigious Barry Goldwater Scholarship—one of only three students from UMass to receive the honor! Click here to read more about her award.
Kim led the Walsh Lab's first laser shock GUP beamtime at the Dynamic Compression Sector at the Advanced Photon Source, collecting our first in situ XRD and VISAR dataset!
Paul's paper reporting the high-pressure bulk synthesis of cobalt cementite in the laser-heated diamond anvil cell has been published in Chemistry of Materials. Great work, Paul!
Kim was awarded an Honorable Mention in this year's NSF GRFP—one of only two in the department. Congratulations, Kim!
Kim joined our awesome collaborators at Lawrence Livermore National Laboratory to perform experiments (remotely) on the Matter in Extreme Conditions endstation at SLAC National Accelerator Laboratory.
Welcome to Scott Ambos, who is now officially a member of the Walsh Lab! Scott joins us from Union College where he worked with Prof. Michael Hagerman on functionalized CdSe quantum dots for water-processable inkjet printed photovoltaics.
Kim virtually attended the UXSS held by Stanford University. Thank you to the organizers for a great workshop!
Our Rigaku Synergy-S single crystal diffractometer was delivered and commissioned in the basement of LGRT. It has a Cu/Ag dual source and is fitted with the HyPix-6000HE hybrid photon counting detector. We are very excited to begin putting it to use!
The lab spent two days meeting and catching up with other researchers in the high pressure field at the annual HPCAT Conference held at the Advanced Photon Source.
Welcome to the first graduate students to join the Walsh Lab: Kimberly Bolduc, Nicholas Manganaro, Paul Marshall, and Scott Thiel. We are excited to get started!