Size reduction-induced chain breaking in Haldane-chain compounds SrNi2-xMgxV2O8 (x=0 and 0.1)

作者:Yue, X. Y.; Ouyang, Z. W.*; Sun, Y. C.; Xia, Z. C.; Rao, G. H.
来源:Journal of Physics: Condensed Matter , 2017, 29(24): 245802.
DOI:10.1088/1361-648X/aa7039

摘要

We report size reduction-induced chain breaking in the spin-1 Haldane-chain SrNi2-xMgxV2O8 (x = 0 and 0.1) by magnetization and electron spin resonance measurements. For x = 0.0, the magnetic susceptibility of all samples can be well described by a temperature-independent term, a Curie-Weiss term and a Haldane-gap term. This implies that a reduced sample grain size breaks the long chain and creates a considerable number of S = 1/2 edge spins, resulting in the enhancement of magnetization and the decrease of Haldane gap in the samples. These edge spins as well as the other paramagnetic ions at grain boundary and surface might be weakly coupled with each other. For the Mg-doped sample with x = 0.1, there are more S = 1/2 spins creased in relative to x = 0.0 because of a combined effect of lattice defects, Mg-doping and reduced size. In addition, the antiferromagnetic resonance of x = 0.1 is also presented.