Temperaturedependent magnetic anisotropy from pseudodipolar interactions
Abstract
Magnetic anisotropy of spin models with pseudodipolar interactions is theoretically studied in the hightemperature paramagnetic phase. Using the hightemperature expansion, we show that the pseudodipolar interaction gives rise to a magnetic anisotropy which shows ∝T^{5} temperature dependence. This phenomenon arises from the pseudodipolar interaction and is distinct from the orbital effect, such as Van Vleck susceptibility. By an explicit calculation, it is shown that the second order in the hightemperature expansion prefers to point the spins along the bond direction. The theory is applied to the HeisenbergKitaev model on the honeycomb lattice and a cubic lattice model which is potentially relevant to perovskite oxides. The leading order for the magnetic anisotropy arises from the second order in hightemperature expansion, which contribute to a fourthorder anisotropic term in Landau theory. The result shows that the anisotropy from the pseudodipolar interaction gives rise to <100 > magnetic anisotropy. These results are potentially relevant to heavytransitionmetal oxides such as iridates. Experimental observation of the magnitude of anisotropic interactions using magnetic torque measurement is also discussed.
 Publication:

Physical Review B
 Pub Date:
 May 2017
 DOI:
 10.1103/PhysRevB.95.184413
 arXiv:
 arXiv:1612.00057
 Bibcode:
 2017PhRvB..95r4413I
 Keywords:

 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 9 pages, 3 figures