Microstrueturc and Mcehanieal Propcrtics of Heat-treated GeSb2Te4 Thin Films

The effect of annealing on microstructure, adhesive and frictional properties of GeSb2Te4 films were experimentally studied. The GeSb2Te4 films were prepared by radio frequency （RF） magnetron sputtering, and annealed at 200℃ and 340℃ under vacuum circumstance, respectively. The adhesion and friction experiments were mainly conducted with a lateral force microscope （LFM） for the GeSb2Te4 thin films before and after annealing. Their morphology and phase structure were analyzed by using atomic force microscopy （AFM） and X-ray Diffraction （XRD） techniques, and the nanoindention was employed to evaluate their hardness values. Moreover, an electric force microscope （EFM） was used to measure the surface potential. It is found that the deposited GeSb2Te4 thin film undergoes an amorphous-to-fcc and fcc-to-hex structure transition; the adhesion has a weaker dependence on the surface roughness, but a certain correlation with the surface potential of GeSb2Te4 thin films. And the friction behavior of GeSb2Te4 thin films follows their adhesion behavior under a lower applied load. However, such a relation is replaced by the mechanical behavior when the load is relatively higher. Moreover, the GeSb2Te4 thin film annealed at 340℃ presents a lubricative property.

Microstructure and mechanical properties of heat-treated GeSb2Te4 thin films

The effect of annealing on microstructure, adhesive and frictional properties of GeSb₂Te₄ films were experimentally studied. The GeSb₂Te₄ films were prepared by radio frequency (RF) magnetron sputtering, and annealed at 200 °C and 340 °C under vacuum circumstance, respectively. The adhesion and friction experiments were mainly conducted with a lateral force microscope (LFM) for the GeSb₂Te₄ thin films before and after annealing. Their morphology and phase structure were analyzed by using atomic force microscopy (AFM) and X-ray Diffraction (XRD) techniques, and the nanoindention was employed to evaluate their hardness values. Moreover, an electric force microscope (EFM) was used to measure the surface potential. It is found that the deposited GeSb₂Te₄ thin film undergoes an amorphous-to-fcc and fcc-to-hex structure transition; the adhesion has a weaker dependence on the surface roughness, but a certain correlation with the surface potential of GeSb₂Te₄ thin films. And the friction behavior of GeSb₂Te₄ thin films follows their adhesion behavior under a lower applied load. However, such a relation is replaced by the mechanical behavior when the load is relatively higher. Moreover, the GeSb₂Te₄ thin film annealed at 340 °C presents a lubricative property. Funded by the National Natural Science Foundation of China (No.50475124), the Foundation for the Author of National Excellent Doctoral Dissertation of China (No. 200330) and New Century Excellent Talents in University (NCET-04-0515)