NMR, magnetization, and heat capacity studies of the uniform spin- 12 chain compound Bi6V3O16

T Chakrabarty,P L Paulose,I Heinmaa,V Yu Verchenko,R Stern

doi:10.1103/physrevb.100.094431

Abstract

We report the local (NMR) and bulk (magnetization and heat capacity) properties of the vanadium-based S=1/2 uniform spin chain compound Bi6V3O16(Bi4V2O10.66). In the low-temperature {\alpha} phase, the magnetic ions (V4+) are arranged in one-dimensional chains. The magnetic susceptibility shows a broad maximum around 50 K signifying a short-range magnetic order. Heat capacity measurements also reveal low-dimensional magnetism. The 51V magic angle spinning nuclear magnetic resonance measurements clearly show that the magnetic V4+ and nonmagnetic V5+ species are located on different crystallographic sites with no mixed occupation. The spin susceptibility calculated from the shift of the 51V NMR spectra reproduces the behavior observed in magnetic susceptibility and agrees well with the S=1/2 uniform spin chain model with J=113(5) K.

Highlights

Magnetism in one-dimensional (1D) Heisenberg antiferromagnetic (AFM) spin systems has remained an area of wide interest in condensed-matter physics since 1970s [1,2]
The magnetic heat capacity confirms the existence of lowdimensional magnetism in the system, even though the lattice part has a dominant contribution to the total heat capacity, and approximation by any model is not decisive
The spin susceptibility calculated from the magic angle spinning nuclear magnetic resonance (MAS-NMR) experiments agrees well with the uniform

Summary

INTRODUCTION

Magnetism in one-dimensional (1D) Heisenberg antiferromagnetic (AFM) spin systems has remained an area of wide interest in condensed-matter physics since 1970s [1,2]. The vanadium-based compound Bi6V3O16 (often described as Bi4V2O10.66) at low temperatures This system is a member of the well-known pseudobinary oxide systems Bi2O3-V2O5, which received significant interest because of their different structural varieties and rich functional properties [30,31], which led to a very efficient bismuth-metal-vanadia (BiMeVOX) family of anionic conductors [32,33]. They exhibit three polymorphs, α, β, and γ , each associated with a different temperature range, where the α phase is the low-temperature one One of these Aurivillius vanadates, Bi4V2O10, which contains all the vanadium ions in the V4+ oxidation state, was studied thoroughly via crystal structure, electron diffraction, and thermodynamic properties about two decades ago [36,37]. The frequency shifts are given relative to the VOCl3 reference

Magnetic susceptibility

Heat capacity

Room-temperature magic angle spinning NMR

CONCLUSION AND OUTLOOK