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Anomalous evolution of the magnetocaloric effect in dilute triangular Ising antiferromagnets Tb\(_{1–x}\)Y\(_x\)(HC O\(_2\))\(_3\)

Falsaperna, Mario, Bulled, Johnathan M., Stenning, Gavin B. G., Goodwin, Andrew L., Saines, P.J. (2022) Anomalous evolution of the magnetocaloric effect in dilute triangular Ising antiferromagnets Tb\(_{1–x}\)Y\(_x\)(HC O\(_2\))\(_3\). Physical Review Materials, 6 (12). Article Number 124410. ISSN 2475-9953. (doi:10.1103/PhysRevMaterials.6.124410) (KAR id:98725)


We investigate the effects of diamagnetic doping in the solid-solution series Tb\(_{1–x}\)Y\(_x\)(HC O\(_2\))\(_3\), in which the parent Tb(HC O\(_2\))\(_3\) phase has previously been shown to host a combination of frustrated and quasi-1D physics, giving rise to a triangular Ising antiferromagnetic ground state that lacks long range 3D order. Heat capacity measurements show three key features: (i) a low temperature Schottky anomaly is observed, which is constant as a function of x; (ii) the transition temperature and associated entropy change are both surprisingly robust to diamagnetic doping; and (iii) an additional contribution at T < 0.4 K appears with increasing x. The origin of this unusual behaviour is rationalised in terms of the fragmentation of quasi-1D spin chains by the diamagnetic Y\(^{3+}\) dopant. Magnetocaloric measurements show a nonlinear dependence on x. The mass-weighted magnetocaloric entropy decreases across the series from the promising values in (HC O\(_2\))\(_3\); however, the magnetocaloric entropy per magnetic Tb\(^{3+}\) ion first decreases then increases with increasing x. Our results establish Tb\(_{1–x}\)Y\(_x\)(HC O\(_2\))\(_3\) as a model system in which to explore the functional ramifications of dilution in a low dimensional magnet.

Item Type: Article
DOI/Identification number: 10.1103/PhysRevMaterials.6.124410
Additional information: For the purpose of open access, the author(s) has applied a Creative Commons Attribution (CC BY) licence to any Author Accepted Manuscript version arising.
Subjects: Q Science > QD Chemistry
Divisions: Divisions > Division of Natural Sciences > Chemistry and Forensics
Funders: Leverhulme Trust (
Engineering and Physical Sciences Research Council (
European Research Council (
Depositing User: Paul Saines
Date Deposited: 06 Dec 2022 10:14 UTC
Last Modified: 12 Dec 2023 12:30 UTC
Resource URI: (The current URI for this page, for reference purposes)

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