TY - JOUR
T1 - Frustrated magnetism in the layered triangular lattice materials K2Co(SeO3)2 and Rb2Co(SeO3)2
AU - Zhong, Ruidan
AU - Guo, Shu
AU - Cava, R. J.
N1 - Funding Information:
The material synthesis, magnetic, and thermodynamic characterization were supported by the Gordon and Betty Moore EPiQS program, through Grant No. GBMF-4412. The crystal structure determination was supported as part of the Institute for Quantum Matter, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award No. DE-SC0019331.
Publisher Copyright:
© 2020 American Physical Society.
PY - 2020/8
Y1 - 2020/8
N2 - A study of the layered triangular lattice materials K2Co(SeO3)2 and Rb2Co(SeO3)2 is reported. These isostructural compounds crystallize in the trigonal space group R-3m (No. 166). The magnetic Co2+ ions form a spin-1/2 triangular lattice and display strongly frustrated magnetism. We find no evidence in the susceptibility or heat capacity for in-plane ordering of the spins; rather the in-plane inverse susceptibility is typical of that seen for frustrated magnets. At around 10 K, a ferromagnetic component appears in the magnetic susceptibility perpendicular to the triangular planes. The heat capacity at low applied fields does not show sharp features, but in larger applied fields a sharp ferromagneticlike transition appears. Field- and direction-dependent magnetization measurements at 2 K indicate that both materials have a magnetic easy axis perpendicular to the triangular planes. The magnetic properties are sensitive to the field applied perpendicular to the triangular planes, which induces a metamagnetization transition at 0.75 T. Spin polarization develops along with the increasing out-of-plane field, resulting in a saturated ferromagnetic state at high fields. In contrast, the magnetic properties are resistant to the in-plane field. Our results suggest that these materials are embodiments of Ising spins on triangular lattices with easy-axis anisotropy.
AB - A study of the layered triangular lattice materials K2Co(SeO3)2 and Rb2Co(SeO3)2 is reported. These isostructural compounds crystallize in the trigonal space group R-3m (No. 166). The magnetic Co2+ ions form a spin-1/2 triangular lattice and display strongly frustrated magnetism. We find no evidence in the susceptibility or heat capacity for in-plane ordering of the spins; rather the in-plane inverse susceptibility is typical of that seen for frustrated magnets. At around 10 K, a ferromagnetic component appears in the magnetic susceptibility perpendicular to the triangular planes. The heat capacity at low applied fields does not show sharp features, but in larger applied fields a sharp ferromagneticlike transition appears. Field- and direction-dependent magnetization measurements at 2 K indicate that both materials have a magnetic easy axis perpendicular to the triangular planes. The magnetic properties are sensitive to the field applied perpendicular to the triangular planes, which induces a metamagnetization transition at 0.75 T. Spin polarization develops along with the increasing out-of-plane field, resulting in a saturated ferromagnetic state at high fields. In contrast, the magnetic properties are resistant to the in-plane field. Our results suggest that these materials are embodiments of Ising spins on triangular lattices with easy-axis anisotropy.
UR - http://www.scopus.com/inward/record.url?scp=85092149427&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85092149427&partnerID=8YFLogxK
U2 - 10.1103/PhysRevMaterials.4.084406
DO - 10.1103/PhysRevMaterials.4.084406
M3 - Article
AN - SCOPUS:85092149427
SN - 2475-9953
VL - 4
JO - Physical Review Materials
JF - Physical Review Materials
IS - 8
M1 - 084406
ER -