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

The magnetization process of multilayered films [Co(30 Angstrom)/Si(5 Angst rom)/Gd(75 Angstrom)/Si(5 Angstrom)](20) having a ferrimagnetic ordering of the magnetic moments of the cobalt and gadolinium layers and a compensatio n temperature T-comp approximate to 118 K is studied by magnetometric and m agnetooptical methods. A magnetic-field-induced spin-orientation transition from the collinear to the noncollinear state is observed. The transition f ield is determined and the H-T magnetic phase diagram is constructed for th e multilayered ferrimagnet Gd/Si/Co in the temperature interval 5-140 K. Th e phase diagram is also calculated in the framework of molecular field theo ry, and satisfactory agreement with the experimental results is obtained. T he constant of the antiferromagnetic exchange interaction between the cobal t and gadolinium layers is established. (C) 2001 American Institute of Phys ics.