TY - JOUR
T1 - Exotic Magnetic Field-Induced Spin-Superstructures in a Mixed Honeycomb-Triangular Lattice System
AU - Garlea, V. Ovidiu
AU - Sanjeewa, Liurukara D.
AU - McGuire, Michael A.
AU - Batista, Cristian D.
AU - Samarakoon, Anjana M.
AU - Graf, David
AU - Winn, Barry
AU - Ye, Feng
AU - Hoffmann, Christina
AU - Kolis, Joseph W.
N1 - Publisher Copyright:
© 2019 authors. Published by the American Physical Society.
PY - 2019/2/26
Y1 - 2019/2/26
N2 - The temperature-magnetic field phase diagram of the mixed honeycomb-triangular lattice system K2Mn3(VO4)2CO3 is investigated by means of magnetization, heat-capacity, and neutron-scattering measurements. The results indicate that triangular and honeycomb magnetic layers undergo sequential magnetic orderings and act as nearly independent magnetic sublattices. The honeycomb sublattice orders at about 85 K in a Neél-type antiferromagnetic structure, while the triangular sublattice displays two consecutive ordered states at much lower temperatures, 3 and 2.2 K. The ground state of the triangular sublattice consists of a planar "Y" magnetic structure that emerges from an intermediate collinear "up-up-down" state. Applied magnetic fields parallel or perpendicular to the c axis induce exotic ordered phases characterized by various spin-stacking sequences of triangular layers that yield bilayer, three-layer, or four-layer magnetic superstructures. The observed superstructures cannot be explained in the framework of quasiclassical theory based only on nearest-neighbor interlayer coupling and point towards the presence of effective second-nearest-neighbor interactions mediated by fluctuations of the magnetic moments in the honeycomb sublattice.
AB - The temperature-magnetic field phase diagram of the mixed honeycomb-triangular lattice system K2Mn3(VO4)2CO3 is investigated by means of magnetization, heat-capacity, and neutron-scattering measurements. The results indicate that triangular and honeycomb magnetic layers undergo sequential magnetic orderings and act as nearly independent magnetic sublattices. The honeycomb sublattice orders at about 85 K in a Neél-type antiferromagnetic structure, while the triangular sublattice displays two consecutive ordered states at much lower temperatures, 3 and 2.2 K. The ground state of the triangular sublattice consists of a planar "Y" magnetic structure that emerges from an intermediate collinear "up-up-down" state. Applied magnetic fields parallel or perpendicular to the c axis induce exotic ordered phases characterized by various spin-stacking sequences of triangular layers that yield bilayer, three-layer, or four-layer magnetic superstructures. The observed superstructures cannot be explained in the framework of quasiclassical theory based only on nearest-neighbor interlayer coupling and point towards the presence of effective second-nearest-neighbor interactions mediated by fluctuations of the magnetic moments in the honeycomb sublattice.
UR - http://www.scopus.com/inward/record.url?scp=85063347949&partnerID=8YFLogxK
U2 - 10.1103/PhysRevX.9.011038
DO - 10.1103/PhysRevX.9.011038
M3 - Article
AN - SCOPUS:85063347949
SN - 2160-3308
VL - 9
JO - Physical Review X
JF - Physical Review X
IS - 1
M1 - 011038
ER -