Specific Heat of the Ce(Ni_{1 - x}Cu_x)₄Mn Compounds

Abstract

Specic heat of the Ce(Ni1−xCux)4Mn compounds has been studied. The samples are prepared by induction melting and it is found, based on the X-ray diraction, that all the compounds keep the CaCu5-type structure. This series exhibits a transition between the ferromagnetically ordered CeNi4Mn and the spin-glass CeCu4Mn compounds, which is well visible in the measurements of the ac susceptibility peak as a function of the magnetic eld frequency and in the magnetization relaxation. In the present research we explore the behavior of the specic heat for various x. The changes of the electronic specic heat coecient γ are determined by analysis of the low temperature part of the Cp/T (T 2 ) dependence. We also observe that the magnetic phase transition is only detectable in the specic heat signal after extraction of the magnetic contribution of the Mn atoms. This is carried out by subtraction of the specic heat of the reference sample.

Magnetic Properties of Ce(Cu_{x}Ni_{1-x})_{4}Mn Compounds

“…In the previous study [1,2] we have shown for CeCuNi 3 Mn that the Cu substitution develops a spin-glass (SG) state. To further investigate this SG behaviour we have now prepared a number of samples in the series Ce(Cu x Ni 1−x ) 4 Mn.…”