Dynamic spin susceptibility of paramagnetic spinel LiV2O4

TL;DR

This paper calculates the dynamical spin susceptibility of LiV2O4 using a weak coupling approach with RPA, explaining neutron scattering data and linking spin fluctuations to specific heat in a geometrically frustrated lattice.

Contribution

It introduces a RPA-based calculation of hi(Q,w) for LiV2O4, incorporating lattice frustration and an adjustable parameter, to interpret neutron scattering results.

Findings

Enhanced magnetic response near a spherical Q-space surface.

Calculated spin relaxation rate matches experimental data.

Estimated spin fluctuation contribution to specific heat.

Abstract

In an attempt to explain inelastic neutron scattering data for LiV2O4 the dynamical spin susceptibility \chi(Q,w) at zero temperature is calculated. Starting point is a weak coupling approach based on the LDA bandstructure for that material. It is supplemented by a RPA treatment of local on-site interactions and contains an adjustable parameter. Due to the geometrically frustrated lattice structure the magnetic response is strongly enhanced in the vicinity of a nearly spherical surface in Q-space. We compare these results with recent low-temperature neutron scattering data. The measured spin relaxation rate \Gamma is used to estimate the spin fluctuation contribution to the specific heat.