1/3 Magnetization Plateau Induced by Magnetic Field in Monoclinic CoV₂O₆

Abstract

It was recently observed by He et al. [ J. Am. Chem. Soc. 2009 , 131 , 7554 ] that the monoclinic CoV(2)O(6) shows an unusual magnetic behavior with a magnetization plateau at the height of 1/3 saturated magnetization, and the critical magnetic field for the second jump in magnetization is about 2 times as large as that for the first one. By using the Wang-Landau simulation, we show that this stepwise magnetic behavior can be well reproduced in a distorted antiferromagnetic triangular model with anisotropic exchange interactions. The 1/3 magnetization plateau here originates from the same ferrimagnetic state as observed in the regular triangular system, but the critical fields show different features due to the frustration relaxed by anisotropy. The relative value of the weakest interaction plays a key role in this stepwise magnetic behavior, and hereby the critical fields of the magnetization plateau can be accurately modulated by tuning exchange interactions, which provides a wide-use principle for the phenomena of 1/3 magnetization plateau observed in experiments.