Thickness dependence and magnetization behavior of Mn-doped GeTe phase change materials

摘要

In this paper, the thickness dependences of microstructural, magnetic and electrical properties of Mn-doped GeTe phase change magnetic thin films were studied. The X-ray diffraction patterns demonstrate that the as-deposited films with difference thickness are amorphous while the annealed films are polycrystalline. The crystal-lographic structure investigation shows that the dominant orientation is enhanced with increasing thickness. The lattice parameters of Mn-doped GeTe thin films as function of the thickness were calculated. The grain sizes increase with the films thickness while the full width at half maximum, plane distance and the lattice strain decrease. The temperature dependences of magnetizations of all the films show that the maximum magnetization values occur at the lowest temperature. The data analysis results of the field cooling magnetization showed that Mn-doped GeTe films have the ferromagnetic ordering at T_C = 48, 97 and 110 K for film with thickness 60, 120 and 200 nm respectively. It was found that the resistivity decreases from 12.6 to 0.863 mΩ cm as the film thickness increases from 60 to 200 nm.