Thin Solid Films, Vol.367, No.1-2, 189-192, 2000
Magnetic anisotropy in MBE-grown epitaxial gadolinium ultra-thin films
The structure and magnetic properties of gadolinium thin films in two systems: W/Gd/W and Y/Gd/Y were studied. Gd films were grown epitaxially on tungsten and yttrium buffer layers in UHV MBE facility using e-guns as the evaporation source. Monocrystalline sapphire substrates with (1 1 (2) over bar 0) crystallographic orientation were used. Critical thickness of d(c) = 3 Angstrom for gadolinium deposited epitaxially on tungsten was determined - in the first monolayer lattice expansion of 3.5% was observed comparing to the bulk gadolinium. Significant decrease of Curie temperature with decreasing of Gd thickness was found. In Y/Gd/Y system for all studied range of Gd thickness (160 > X > 9 Angstrom) inplane anisotropy was observed. On the contrary, in W/Gd/W system for Gd thickness below 40 Angstrom the transition from in-plane to perpendicular anisotropy took place.