Magnetic susceptibility and heat capacity investigations of the unconventional spin-chain compound Sr3CuPtO6

TL;DR

This study investigates the magnetic and thermal properties of Sr3CuPtO6, an unconventional spin-chain compound with a zigzag structure and separated Cu atoms, revealing behavior consistent with a S=1/2 Heisenberg model but with low-temperature deviations.

Contribution

It provides experimental data on an unconventional spin chain compound and compares it with theoretical models, highlighting the effects of its unique structure.

Findings

Good agreement with S=1/2 Heisenberg model

Intra-chain coupling constants are consistent across methods

Low-temperature heat capacity shows deviations suggesting a possible energy gap

Abstract

The Heisenberg spin chain compound Sr3CuPtO6 is investigated by magnetic susceptibility and heat capacity measurements. Sr3CuPtO6 has an unconventional chain structure in the sense that i) the spin half copper atoms are arranged in a zigzag chain structure, and ii) neighboring Cu atoms along the chains are separated by spin zero platinum atoms. We report that this compound shows broad features in the temperature dependence of both the magnetic contribution to the heat capacity and the magnetic susceptibility. Despite the unconventional nature of the spin chain structure, this set of data exhibits good agreement with theoretical models for a classical S = 1/2 Heisenberg spin chain compound. The values of the intra-chain coupling constant, obtained by different techniques, are found to be very close to each other. The low temperature heat capacity data (below ~ 6 K) exhibit a deviation from the theoretically expected behavior, which could be related to a small energy gap in the spin excitation spectrum.