One-dimensional tellurium chains: Crystal structure and thermodynamic properties of PrCuxTe2 (x ~ 0.45)
One-dimensional tellurium chains: Crystal structure and thermodynamic properties of PrCuxTe2 (x ~ 0.45)
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DOI：
10.1016/j.jssc.2018.10.008
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发表时间：
2019-01
影响因子：
3.3
通讯作者：
R. Baumbach;L. Balicas;G. McCandless;P. Sotelo;Q. Zhang;Jess Evans;Dino Camdzic;T. J. Martin;J. Chan;R. Macaluso
中科院分区：
文献类型：
--
作者：
R. Baumbach;L. Balicas;G. McCandless;P. Sotelo;Q. Zhang;Jess Evans;Dino Camdzic;T. J. Martin;J. Chan;R. Macaluso
本文报道了稀土-硫族化合物三元系PrCu_（0.45）Te_2及其非四元系LaCu_（0.40）Te_2的X射线衍射、晶体结构、磁化强度和热容量。PrCu_（0.45）Te_2的晶体结构为CuTe_4四面体共棱共角链状结构，Pr以Cu和Te组成的多面体为中心。Cu位点被部分占据，并表现出局部无序的特征。磁化率测量表明居里-外斯温度依赖性与Pr 3+状态一致。没有磁有序观察到1.8 K，但负居里-外斯温度表明反铁磁交换相互作用。重要的是，与LaCu0.40Te2相比，PrCu0.45Te2的低温热容量大大增强，这表明存在与来自Pr 3+离子的4f-电子相关的熵的积累。这些特征揭示了可能的旋转挫败行为，并引入这一系列材料作为研究新现象的模板。
X-ray diffraction, crystal structure, magnetization, and heat capacity results are presented for the rare earth – chalcogenide ternary system PrCu0.45Te2and its non-4fanalogue LaCu0.40Te2. The crystal structure of PrCu0.45Te2is characterized by chains of edge and corner-sharing CuTe4tetrahedra and Pr centered in polyhedra comprised of Cu and Te. The Cu site is partially occupied and exhibits signatures of local disorder. Magnetic susceptibility measurements show a Curie-Weiss temperature dependence consistent with a Pr3+state. No magnetic ordering is observed down to 1.8 K, but the negative Curie-Weiss temperature suggests an antiferromagnetic exchange interaction. Importantly, the low temperature heat capacity of PrCu0.45Te2is strongly enhanced by comparison to LaCu0.40Te2, suggesting that there is a build-up of entropy that is associated with the 4f-electrons from the Pr3+ions. These features reveal possible spin frustration behavior and introduce this family of materials as a template for studying new phenomenon.