Magnetic Phase Transitions in (Tb,Y)Mn2M2 (M=Ge and Si) Systems

Authors

I. S. Dubenko, Southern Illinois University Carbondale
I. Yu. Gaidukova, Moscow State University
S. A. Granovsky, Moscow State University
K. Inoue, Institute for Molecular Science
A. S. Markosyan, Moscow State University
S. Roy, Southern Illinois University Carbondale
N. Ali, Southern Illinois University Carbondale

Comments

© 2003 American Institute of Physics

Published in Journal of Applied Physics, Vol. 93 No. 10 (2003) at doi: 10.1063/1.1541652

Abstract

The temperature- and field-induced magnetic phase transitions in pseudoternary systems Tb_1−xY_xMn₂Ge₂ and Tb_1−xY_xMn₂Si₂, which are characterized by a separate magnetic ordering of the Mn and Tb subsystems, have been studied on strongly textured samples by magnetization and thermal expansion measurements. In the concentration region 0.4≤ x≤ 1.0, where the Mn moments are ordered only, the magnetic structure is antiferromagnetic. The magnetic ordering in the Tb subsystem is accompanied by a transformation of the Mn magnetic structure. As a result, the compounds show a spontaneous magnetization. This transition is of a first-order type. In both systems the transition temperature for the Tb subsystem T_C^(Tb) decreases linearly with increasing Y concentration and goes to zero at about x=0.40. Canted phases and field-induced first-order transitions into the collinear phase have been observed in both systems below this temperature. It is concluded that the f–d exchange interaction is the primary factor governing the value of T_C^(Tb).

Recommended Citation

Dubenko, I. S., Gaidukova, I. Y., Granovsky, S. A., Inoue, K., Markosyan, A. S., Roy, S. and Ali, N.. "Magnetic Phase Transitions in (Tb,Y)Mn2M2 (M=Ge and Si) Systems." (May 2003).