The spin relaxation in chromium spinel oxides ACr2O4 (A= Mg, Zn, Cd) is investigated in the paramagnetic regime by electron spin resonance (ESR). The temperature dependence of the ESR linewidth indicates an unconventional spin-relaxation behavior, similar to spin-spin relaxation in the two-dimensional (2D) chromium-oxide triangular lattice antiferromagnets. The data can be described in terms of a generalized Berezinskii-Kosterlitz-Thouless (BKT) type scenario for 2D systems with additional internal symmetries. Based on the characteristic exponents obtained from the evaluation of the ESR linewidth, short-range order with a hidden internal symmetry is suggested.
@article{arxiv.1705.02234,
title = {Berezinskii-Kosterlitz-Thouless Type Scenario in Molecular Spin Liquid $A$Cr$_2$O$_4$},
author = {Mamoun Hemmida and Hans-Albrecht Krug von Nidda and Vladimir Tsurkan and Alois Loidl},
journal= {arXiv preprint arXiv:1705.02234},
year = {2017}
}