Faculty of Mathematics and Physics, Department of Condensed Matter Physics, Charles University, Ke Karlovu 5, 121 16 Prague 2, Czech Republic.
J Phys Condens Matter. 2010 Mar 31;22(12):126002. doi: 10.1088/0953-8984/22/12/126002. Epub 2010 Mar 8.
We report on specific-heat measurements of the heavy-fermion compounds Ce(1 - x)Y(x)PdAl (0 ≤ x ≤ 1) between 0.35 and 300 K and in magnetic fields up to 14 T. Ce(1 - x)Y(x)PdAl compounds crystallize in the hexagonal ZrNiAl-type structure and CePdAl orders antiferromagnetically below T(N) = 2.8 K. The specific heat measured in external magnetic fields is also consistent with the antiferromagnetic order and the phase transition to the ferromagnetic state in fields around 4 T. The temperature dependence of the magnetic specific heat in CePdAl indicates magnetic correlations far above T(N). Substitution of nonmagnetic Y for magnetic Ce ions reduces T(N) rapidly and the antiferromagnetic order vanishes around x = 0.2. The Sommerfeld coefficient γ of the electronic specific heat is temperature dependent and increases strongly at low temperatures for all Ce concentrations.
我们报告了重费米子化合物 Ce(1 - x)Y(x)PdAl（0 ≤ x ≤ 1）在 0.35 到 300 K 之间以及高达 14 T 的磁场中的比热测量结果。Ce(1 - x)Y(x)PdAl 化合物在六方 ZrNiAl 型结构中结晶，CePdAl 在 T(N) = 2.8 K 以下反铁磁有序。在外部磁场中测量的比热也与反铁磁有序和在约 4 T 的磁场中转变为铁磁态一致。CePdAl 中磁比热的温度依赖性表明磁相关性远高于 T(N)。用非磁性 Y 取代磁性 Ce 离子会迅速降低 T(N)，并且反铁磁有序在 x = 0.2 左右消失。电子比热的 Sommerfeld 系数 γ 随温度变化，对于所有 Ce 浓度，在低温下都会强烈增加。
