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Separation of energy scales in the kagome antiferromagnet TmAgGe: a magnetic-field-orientation study up to 55 T

P. A. Goddard·J. Singleton·A. L. Lima-Sharma·E. Morosan·S. J. Blundell·S. L. Bud'ko·P. C. Canfield
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Abstract

TmAgGe is an antiferromagnet in which the spins are confined to distorted kagome-like planes at low temperatures. We report angle-dependent measurements of the magnetization $M$ in fields of up to 55 T that show that there are two distinct and separate energy scales present in TmAgGe, each responsible for a set of step-like metamagnetic transitions; weak exchange interactions and strong crystalline electric field (CEF) interactions. Simulations of $M$ using a three-dimensional, free-energy minimization technique allow us to specify for the first time the physical origin of the metamagnetic transitions in low, in-plane fields. We also show that the transitions observed with the field perpendicular to the kagome planes are associated with the CEF-split multiplet of Tm.

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P. A. Goddard, J. Singleton, A. L. Lima-Sharma, E. Morosan, S. J. Blundell, S. L. Bud'ko, P. C. Canfield. 2006-11-17. Separation of energy scales in the kagome antiferromagnet TmAgGe: a magnetic-field-orientation study up to 55 T. https://doi.org/10.1103/physrevb.75.094426

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