Structure and magnetic properties of nanostructured GdTb thin films

Various series of Gd100-xTbx films and multilayers with a different thickness of rare earth (RE) layers were prepared by rf-sputtering. The increase of Gd content leads to an increase of the magnetic ordering temperature (T-ord). At the same time substitution of the low anisotropic gadolinium by high anisotropic terbium causes an increase of the coercivity of the samples. The decrease of the RE layer thickness (L-RE) results in the change of the RE films structure: the crystalline grain size goes down and for L-RE < 3 nm an amorphous phase appears. For L-RE < 5 nm all compositions show a significant decrease of the ordering temperature. In contrast with bulk Gd100-xTbx alloys, in case of thin films, the value of T-ord can be tailored, not only by the change of the composition, but also by the variation of the thickness of Gd100-xTbx films. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim