Abstract
Colossal magnetoresistance (CMR) has been observed across many Eu2+-based materials; however, its origin is not completely understood. Here we investigate the antiferromagnetic insulator EuZn2P2 through single crystal x-ray diffraction, transmission electron microscopy, electrical transport, magnetization, dilatometry, and electron spin resonance measurements complemented by density functional theory calculations. Our electrical resistivity data reveal a large negative magnetoresistance, MR=[R(H)−R(0)]/R(0), that reaches MR=−99.7% at 9 T near the antiferromagnetic ordering temperature TN=23K. Dilatometry measurements show an accompanying field-induced lattice strain. Additionally, Eu2+ electron spin resonance reveals a strong ferromagnetic exchange interaction between Eu2+ and conduction electrons. Our experimental results in EuZn2P2 are consistent with a magnetic polaron scenario and suggest magnetic polaron formation as a prevailing explanation of CMR in Eu2+-based compounds.
| Original language | English |
|---|---|
| Article number | 104403 |
| Journal | Physical Review Materials |
| Volume | 9 |
| Issue number | 10 |
| DOIs | |
| State | Published - Oct 10 2025 |
Funding
Work at Los Alamos National Laboratory was performed under the auspices of the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering. Scanning electron microscope and energy dispersive x-ray measurements were performed at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is managed by Triad National Security, LLC for the U.S. Department of Energy's NNSA, under Contract No. 89233218CNA000001. Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. M-EELS experiments were supported by the EPiQS program of the Gordon and Betty Moore Foundation Grant No. GBMF9452. C.S.K. gratefully acknowledges the support of the U.S. Department of Energy through the LANL/LDRD Program and the G. T. Seaborg Institute. J.S. acknowledges support from the Los Alamos Institute for Materials Science. M.S.C. acknowledges funding from the LANL Laboratory Directed Research & Development Program. This manuscript has been authored by employees of UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan . Work at Los Alamos National Laboratory was performed under the auspices of the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering. Scanning electron microscope and energy dispersive x-ray measurements were performed at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is managed by Triad National Security, LLC for the U.S. Department of Energy's NNSA, under Contract No. 89233218CNA000001. Work at the Molecular Foundry was supported by the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. M-EELS experiments were supported by the EPiQS program of the Gordon and Betty Moore Foundation Grant No. GBMF9452. C.S.K. gratefully acknowledges the support of the U.S. Department of Energy through the LANL/LDRD Program and the G. T. Seaborg Institute. J.S. acknowledges support from the Los Alamos Institute for Materials Science. M.S.C. acknowledges funding from the LANL Laboratory Directed Research & Development Program.This manuscript has been authored by employees of UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan [69].