Critical behavior of the metallic triangular-lattice Heisenberg antiferromagnet PdCrO2
Critical behavior of the metallic triangular-lattice Heisenberg antiferromagnet PdCrO2
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DOI：
10.1103/physrevb.79.104424
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发表时间：
2009-03-01
影响因子：
3.7
通讯作者：
Maeno, Yoshiteru
中科院分区：
文献类型：
--
作者：
Takatsu, Hiroshi;Yoshizawa, Hideki;Maeno, Yoshiteru
我们报告了导电磁体PdCrO 2的物理性质，该磁体由具有Cr 3+离子三角晶格（S=3/2）的层状结构组成。通过比热、电阻率、磁化率和中子散射测量，我们证实了在T-N=37.5 K时的反铁磁转变。比热的临界行为在T-N以上异常宽的温度范围内持续存在。这一事实意味着自旋关联甚至在比T-N高得多的温度下也会发展。在T-N以上的电阻率的温度依赖性也是由于阻挫自旋之间的短程关联。虽然磁化强度的临界指数与相关模型的预测合理一致，但在宽温度范围内评估的比热与预测有很大不同。
We report physical properties of the conductive magnet PdCrO2 consisting of a layered structure with a triangular lattice of Cr3+ ions (S=3/2). We confirmed an antiferromagnetic transition at T-N=37.5 K by means of specific heat, electrical resistivity, magnetic susceptibility, and neutron-scattering measurements. The critical behavior in the specific heat persists in an unusually wide temperature range above T-N. This fact implies that spin correlations develop even at a much higher temperature than T-N. The observed sublinear temperature dependence of the resistivity above T-N is also attributed to the short-range correlations among the frustrated spins. While the critical exponent for the magnetization agrees reasonably with the prediction of the relevant model, that for the specific heat evaluated in the wide temperature range differs substantially from the prediction.