One-dimensional magnetism in synthetic Pauflerite, $\beta$-VOSO$_4$

TL;DR

This study synthesizes and characterizes $eta$-VOSO$_4$, confirming its behavior as an almost ideal one-dimensional spin-1/2 Heisenberg chain with specific superexchange pathways, through experimental and theoretical methods.

Contribution

It provides the first comprehensive experimental and theoretical analysis of $eta$-VOSO$_4$ as a nearly perfect one-dimensional magnetic system with detailed superexchange pathway identification.

Findings

Magnetic susceptibility and neutron scattering match 1D Heisenberg chain model.

Superexchange pathway runs along the b axis, not the expected a direction.

No long-range magnetic order detected, indicating near-ideal 1D magnetism.

Abstract

We have synthesized single-crystal samples of $\beta$-VOSO$_4$ and fully characterized their magnetic properties. Our magnetic susceptibility, high field magnetization and powder inelastic neutron scattering results are in excellent agreement with theoretical expressions for a one-dimensional spin-1/2 Heisenberg chain with an exchange parameter of $3.83(2)$ meV. Ab initio calculations identify the superexchange pathway, revealing that the spin-chain does not run along the expected crystallographic chain $a$ direction but instead between V$^{4+}$O$_{6}$ octahedra that are linked via SO$_{4}$ tetrahedra along the $b$ axis. We do not detect any phase transition to a long-range magnetic order within our experimental conditions, indicating $\beta$-VOSO$_4$ is very close to an ideal one-dimensional magnetic system.