Spin-density-wave effects in the (Cr_98.4Al_1.6)_{100鈭?span style='font-style: italic'>y}Mo_y alloy system

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• 作者：B. Muchono ; A.R.E. Prinsloo ; C.J. Sheppard ; H.L. Alberts ; A.M. Strydom
• 关键词：Thermopower ; Electrical resistivity ; Specific heat ; Quantum critical behavior ; Spin-density-wave ; Antiferromagnetism ; Sommerfeld coefficient
• 刊名：Journal of Magnetism and Magnetic Materials
• 出版年：March, 2014
• 年：2014
• 卷：354
• 期：Complete
• 页码：222-230
• 全文大小：1901 K

文摘

The possibility of quantum critical behaviour in a spin-density-wave antiferromagnetic (Cr_98.4Al_1.6)_100鈭?em>yMo_y alloy system is investigated through electrical resistivity, Seebeck coefficient and specific heat measurements. Magnetic resistivity anomalies associated with the N茅el transition temperature are highly enhanced in the thermoelectric measurements, allowing for complementary methods in obtaining the N茅el temperatures of these alloys. The results indicate a suppression of the N茅el temperatures to below 2 K for alloy concentrations y鈮?.5. This aspect is strongly reflected in the y-dependence of the residual resistivity and Sommerfeld specific heat coefficient. Both parameters depict rather sharp changes, related to spin-density-wave energy gap influences, on entering the antiferromagnetic phase when y is decreased at 2 K through y_c鈮?.5 on the concentration-temperature magnetic phase diagram. The behaviour of the concentration dependence of the Sommerfeld specific heat coefficient is suggestive of quantum critical behaviour in this alloy system, with a quantum critical point at y鈮?em>y_c.