Enhancement of the crystallization of TbxFe1−x thin films upon the formation of α-Tb phase

Abstract Tb x Fe 1− x thin films deposited by sputtering on Mo were investigated structurally and magnetically. The microstructure 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 microstructure 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 α-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 α-Tb appears to be fundamental to crystallized TbFe 2 on layers deposited on rigid buffers.