H–T phase diagram of a multilayered Gd/Si/Co film with ferrimagnetic ordering of the layers

Abstract

The magnetization process of multilayered films [Co(30 Å)/Si(5 Å)/Gd(75 Å)/Si(5 Å)]20 having a ferrimagnetic ordering of the magnetic moments of the cobalt and gadolinium layers and a compensation temperature Tcomp≈118 K is studied by magnetometric and magnetooptical methods. A magnetic-field-induced spin-orientation transition from the collinear to the noncollinear state is observed. The transition field is determined and the H–T magnetic phase diagram is constructed for the multilayered ferrimagnet Gd/Si/Co in the temperature interval 5–140 K. The phase diagram is also calculated in the framework of molecular field theory, and satisfactory agreement with the experimental results is obtained. The constant of the antiferromagnetic exchange interaction between the cobalt and gadolinium layers is established.