7Li NMR Studies of LiCrO2

Abstract

We report on 7Li NMR studies of a spin S = 3/2 triangular lattice antiferromagnet LiCrO2 (Neel temperature TN = 62 K) in the paramagnetic state by using the free-induction decay of 7Li nuclear magnetization. We observed critical divergence of the 7Li nuclear spin-lattice relaxation rate 1/T1 near TN, a narrow critical region, and a critical exponent w = 0.45 from a fit of 1/T1 $\propto$ (T/TN - 1)$^{-w}$. Although spin frustration effects have been explored for this system, the dynamical critical phenomena suggest that LiCrO2 in the critical region is a poor low dimensional antiferromagnetic system.