Enhancement of the crystallization of Tb_xFe_(1-x) thin films upon the formation of a-Tb phase

摘要

Tb_xFe_(1-x) thin films deposited by sputtering on Mo were investigated structurally and magnetically. The rnicrostructure consists of TbFe_2 nanoparticles embedded in an amorphous matrix, and the Tb content can be correlated with an increase in the volume of these nanoparticles. Similar rnicrostructure and behavior were found when TbFe_2 was deposited on glass and on a Pt buffer layer. Nevertheless, thermal treatments promote a different effect, depending on the mechanical stiffness of the buffer layer. The layers deposited on Mo, a rigid material, show crystalline TbFe_2 together with a-Tb phase upon thermal treatment. In contrast, TbFe_2 does not crystallize properly on Pt, a material with a lower stiffness than Mo. Intermediate results were observed on the film deposited on glass. Experimental results show the impact of the buffer stiffness on the crystallization process. Moreover, the formation of a-Tb appears to be fundamental to crystallized TbFe_2 on layers deposited on rigid buffers.