Weak mid-gap spin susceptibility anomaly of LiVGe2O6 with nonmagnetic impurities - art. no. 134428

The magnetic susceptibility of mid-gap states of the one-dimensional gapped S = 1 Heisenberg model is calculated in this paper. These mid-gap states a re generated by nonmagnetic impurity bonds introduced by crystal defects, s uch as dislocations, stack faults, etc. Using the relation between the gap magnitude of the mid-gap state and the strength of the impurity bond, we ex plain the weak mid-gap spin susceptibility anomaly in the experimental data of LiVGe2O6. We find that the position of the weak anomaly is well explain ed by assuming that it comes from nonmagnetic defects. Our explanation show s that the weak anomaly will be weaker if there are fewer crystal defects a nd nonmagnetic impurities.