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Critical Phenomena and the Quantum Critical Point of Ferromagnetic Zr1-xNbxZn2

D. A. Sokolov·M. C. Aronson·W. Gannon·Z. Fisk
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Abstract

We present a study of the magnetic properties of Zr1-xNbxZn2, using an Arrott plot analysis of the magnetization. The Curie temperature TC is suppressed to zero temperature for Nb concentration xC=0.083+/-0.002, while the spontaneous moment vanishes linearly with TC as predicted by the Stoner theory. The initial susceptibility chi displays critical behavior for x<=xC, with a critical exponent which smoothly crosses over from the mean field to the quantum critical value. For high temperatures and x<=xC and for low temperatures and x>=xC we find that chi^(-1)=chi_o^(-1)+aT^(4/3), where chi_o^(-1) vanishes as x approaches xC. The resulting magnetic phase diagram shows that the quantum critical behavior extends over the widest range of temperatures for x=xC, and demonstrates how a finite transition temperature ferromagnet is transformed into a paramagnet, via a quantum critical point.

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D. A. Sokolov, M. C. Aronson, W. Gannon, Z. Fisk. 2005-12-12. Critical Phenomena and the Quantum Critical Point of Ferromagnetic Zr1-xNbxZn2. https://doi.org/10.1103/physrevlett.96.116404

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