New orthorhombic modification of equiatomic CePdAl
New orthorhombic modification of equiatomic CePdAl
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等原子 CePdAl 的新斜方晶系修饰
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
P. Rogl
中科院分区：
文献类型：
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作者：
A. Gribanov;A. Tursina;E. Murashova;Y. Seropegin;E. Bauer;H. Kaldarar;R. Lackner;H. Michor;E. Royanian;M. Reißner;P. Rogl
从单晶X射线数据确定了一种新的低温改性CePdAl的晶体结构：CePdAl型;空间群Pmmn（No.59），Z = 14，oP 42，a = 0.426 07 nm，B = 2.887 58 nm，c = 0.721 90 nm; RF = 0.048。斜方晶系CePdAl的物理性质受RKKY相互作用、Kondo效应和晶体电场分裂的相互平衡控制，导致在低于2.5K时出现反铁磁有序。电子输运让人想起教科书般的近藤晶格，它在低温下沿着超过50%的显著负磁阻。尽管与CePdAl的六方变体相比，不存在几何挫折，但有序温度TN甚至更小。一个可能的原因是增强近藤相互作用。
The crystal structure of a new low-temperature modification of CePdAl was determined from single-crystal x-ray data: CePdAl-type; space group Pmmn (No. 59), Z = 14, oP42, a = 0.426 07 nm, b = 2.887 58 nm, c = 0.721 90 nm; RF = 0.048. Physical properties of orthorhombic CePdAl are governed by a mutual balance of the RKKY interaction, the Kondo effect and crystalline electric field splitting, resulting in antiferromagnetic ordering below ≈2.5 K. Electronic transport is reminiscent of a textbook-like Kondo lattice, which comes along with a significant negative magnetoresistance of more than 50% at low temperatures. Although geometrical frustration is absent when compared to the hexagonal modification of CePdAl, the ordering temperature TN is even smaller. A possible cause is enhanced Kondo interactions.