TY  - GEN
N2  - High-frequency electron spin resonance is utilised to study antiferromagnetic and ferromagnetic resonance in MnTiO3, LiMnPO4, and CrI3. The main measurement technique is complemented by X-band electron spin resonance and by magnetisation measurements in static and oscillating magnetic fields. For each studied material, a resonance-frequency?magnetic-diagram of the magnon excitations is
constructed and effective anisotropy and exchange constants derived. MnTiO3 is found to be describable by a two-sublattice antiferromagnetic model with uniaxial anisotropy and with effective exchange field BE = 107(6)T and anisotropy field BA = 0.17(1) T. The source of the anisotropy is argued to be magnetic dipole-dipole interactions. LiMnPO4 is found to be a two-sublattice antiferromagnet with orthorhombic anisotropy and effective parameters BE = 37.4(1) T, BcA = 0.22(1) T, and BbA = 0.55(1) T. An anomalous magnon branch is shown to be accountable for by rotation of the anisotropy axis at the spin-flop field by 6.5 degrees towards the hard magnetisation axis. A spin flip along the hard magnetisation axis is detected and suggested to indicate Dzyaloshinskii-Moriya-interaction-caused spin canting in the ground state. CrI3 is shown to possess anisotropy gap delta = 80(1) GHz at 2 K and its closure is detected only at approximately 1.3TC, confirming the quintessential role of anisotropy in formation of long-range ferromagnetic order. Critical-scaling analysis yields beta = 0.21(4), gamma = 1.05(2), and delta = 6.05(1), which are interpreted as indicating a predominantly two-dimensional nature of magnetic interactions.
A1  - Jonák, Martin
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/32377/
ID  - heidok32377
CY  - Heidelberg
AV  - public
Y1  - 2022///
TI  - Low-Energy Magnetic Excitations and Magnetisation in Magnetoelectric Antiferromagnets MnTiO3 and LiMnPO4 and in van-der-Waals Ferromagnet CrI3
ER  -