Analysis of the finite-temperature phase transition of Heisenberg antiferromagnetic compound LiVGe2O6

Abstract

The susceptibility and nuclear magnetic resonance measurements on quasi-one-dimensional spin-1 Heisenberg antiferromagnet LiVGe2O6 indicate that this material shows a phase transition from paramagnetic state to antiferromagnetic Nel state at about 22 K, and there exists a gap in the low-temperature magnetic excitation spectrum. Based on the model Hamiltonian of LiVGe2O6, we propose a low-energy field theoryGinzburg-Landau theory for this compound. From this theory, we study the finite-temperature phase transition induced by spontaneous symmetry breaking and then calculate the finite-temperature susceptibility of LiVGe2O6. All the theoretical calculations are consistent with the experimental results.