TY - JOUR
T1 - High-resolution diffraction reveals magnetoelastic coupling and coherent phase separation in tetragonal CuMnAs
AU - Karigerasi, Manohar H.
AU - Kang, Kisung
AU - Huang, Jeffrey
AU - Peterson, Vanessa K.
AU - Rule, Kirrily C.
AU - Studer, Andrew J.
AU - Schleife, Andre
AU - Huang, Pinshane Y.
AU - Shoemaker, Daniel Philip
N1 - Funding Information:
This work was undertaken as part of the Illinois Materials Research Science and Engineering Center, supported by the National Science Foundation MRSEC program under NSF Award No. DMR-1720633. The characterization was carried out in part in the Materials Research Laboratory Central Research Facilities, University of Illinois. This research used resources of the Spallation Neutron Source, a DOE Office of Science User Facility operated by Oak Ridge National Laboratory, and the Advanced Photon Source, a DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DEAC02-06CH11357. The NPD measurements in Wombat and Echidna beamlines were carried out under the Proposals No. DB8036 and No. MI1931, respectively. We thank Matthias Frontzek for assistance with NPD collection in POWGEN beamline at the Spallation Neutron Source. This work made use of the Illinois Campus Cluster, a computing resource that is operated by the Illinois Campus Cluster Program (ICCP) in conjunction with the National Center for Supercomputing Applications (NCSA) and which is supported by funds from the University of Illinois at Urbana-Champaign.
Publisher Copyright:
© 2022 American Physical Society. AU.
PY - 2022/9
Y1 - 2022/9
N2 - Tetragonal CuMnAs was the first antiferromagnet where reorientation of the Néel vector was reported to occur by an inverse spin galvanic effect. A complicating factor in the formation of phase-pure tetragonal CuMnAs is the formation of an orthorhombic phase with nearly the same stoichiometry. Pure-phase tetragonal CuMnAs has been reported to require an excess of Cu to maintain a single phase in traditional solid state synthesis reactions. Here we show that subtle differences in diffraction patterns signal pervasive inhomogeneity and phase separation, even in Cu-rich Cu1.18Mn0.82As. From calorimetry and magnetometry measurements, we identify two transitions corresponding to the Néel temperature (TN) and an antiferromagnet to weak ferromagnet transition in Cu1.18Mn0.82As and CuMn0.964As1.036. These transitions have clear crystallographic signatures, directly observable in the lattice parameters upon in situ heating and cooling. The immiscibility and phase separation could arise from a spinoidal decomposition that occurs at high temperatures, and the presence of a ferromagnetic transition near room temperature warrants further investigation of its effect on the electrical switching behavior.
AB - Tetragonal CuMnAs was the first antiferromagnet where reorientation of the Néel vector was reported to occur by an inverse spin galvanic effect. A complicating factor in the formation of phase-pure tetragonal CuMnAs is the formation of an orthorhombic phase with nearly the same stoichiometry. Pure-phase tetragonal CuMnAs has been reported to require an excess of Cu to maintain a single phase in traditional solid state synthesis reactions. Here we show that subtle differences in diffraction patterns signal pervasive inhomogeneity and phase separation, even in Cu-rich Cu1.18Mn0.82As. From calorimetry and magnetometry measurements, we identify two transitions corresponding to the Néel temperature (TN) and an antiferromagnet to weak ferromagnet transition in Cu1.18Mn0.82As and CuMn0.964As1.036. These transitions have clear crystallographic signatures, directly observable in the lattice parameters upon in situ heating and cooling. The immiscibility and phase separation could arise from a spinoidal decomposition that occurs at high temperatures, and the presence of a ferromagnetic transition near room temperature warrants further investigation of its effect on the electrical switching behavior.
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U2 - 10.1103/PhysRevMaterials.6.094405
DO - 10.1103/PhysRevMaterials.6.094405
M3 - Article
AN - SCOPUS:85138453267
SN - 2475-9953
VL - 6
JO - Physical Review Materials
JF - Physical Review Materials
IS - 9
M1 - 094005
ER -