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arXiv 0806.1943cond-mat.str-el
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新型非常规反铁磁体Yb $_3$ Pt $_4$

A New Unconventional Antiferromagnet, Yb$_3$Pt$_4$

M. C. Bennett, P. Khalifah, D. A. Sokolov, W. J. Gannon, Y. Yiu, M. S. Kim, C. Henderson, M. C. Aronson

摘要:

本文报道了一种新的二元化合物Yb $_{3}$ Pt $_{4}$单晶的合成和基本性质。该化合物中的Yb离子完全是三价的,并且热容量测量表明,晶场方案涉及双重基态,与激发态很好地分离,在$\sim$ 150 K以上完全占据。的热容量显示一个大的,弱的一阶异常在2.4 K,其中观察到的尖点的磁化率信号的发病反铁磁秩序。与该顺序相关的熵是二重态基态的全部Rln 2,然而有序相中的磁化率由低于Neel温度的大的且与温度无关的分量主导。有序态的热容源于铁磁自旋波,证明了有序态固有的局部矩特征。电阻率异常大,并且恰好在尼尔温度下成为温度的二次方。在热容和磁化率方面没有类似的费米液体行为意味着Yb $_{3}$ Pt $_{4}$是一个低电子密度系统,其中费米表面进一步被磁序的开始所带隙。

英文摘要:

We report the synthesis and basic properties of single crystals of a new binary compound, Yb$_{3}$Pt$_{4}$. The Yb ions in this compound are fully trivalent, and heat capacity measurements show that the crystal field scheme involves a doublet ground state, well separated from the excited states, which are fully occupied above $\sim$ 150 K. The heat capacity displays a large, weakly first order anomaly at 2.4 K, where a cusp is observed in the magnetic susceptibility signalling the onset of antiferromagnetic order. The entropy associated with this order is the full Rln2 of the doublet ground state, however the magnetic susceptibility in the ordered phase is dominated by a large and temperature independent component below the Neel temperature. The heat capacity in the ordered state originates with ferromagnetic spin waves, giving evidence for the inherently local moment character of the ordered state. The electrical resistivity is unusually large, and becomes quadratic in temperature exactly at the Neel temperature. The absence of analogous Fermi liquid behavior in the heat capacity and the magnetic susceptibility implies that Yb$_{3}$Pt$_{4}$ is a low electron density system, where the Fermi surface is further gapped by the onset of magnetic order.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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