Effect of Mg-Film Thickness on the Formation of Semiconductor Mg_2Si Films Prepared by Resistive Thermal Evaporation Method

Mg films of various thicknesses were deposited on Si（111） substrates at room temperature by resistive thermal evaporation method, and then the Mg/Si samples were annealed at 40 ℃ for 4 h. The effects of Mg film thickness on the formation and structure of Mg2Si films were investigated. The results showed that the crystallization quality of Mg2Si films was strongly influenced by the thickness of Mg film. The XRD peak intensity of Mg2Si （220） gradually increased initially and then decreased with increasing Mg film thickness. The XRD peak intensity of Mg2Si （220） reached its maximum when the Mg film of 380 um was used. The thickness of the Mg2Si film annealed at 400℃ for 4 h was approximately 3 times of the Mg film.

Influence of Sputtering Gas on Morphological and Optical Properties of Magnesium Films

The influence of sputtering gas（He Ar） on the structural properties of Mg thin films has been investigated.The optical property（reflectance） that results from the growth of films at varying substrate temperatures（Tsub） was also studied.The deposited films were characterized by using X-ray diffraction（XRD）,field emission scaning electron microscopy（FE-SEM）,atomic force microscopy（AFM） and UV-Vis-NIR spectrophotometer.The smaller crystallite size and lower deposition rate were observed in the presence of Helium atmosphere compared to Argon.Morphology of the films shows 2D hexagonal geometry of grains in the deposition temperature range（Tsub≈50-150℃） in both the sputtering gases.The surface roughness of the polycrystalline films were found to increase with increase in the deposition temperature of both ambient gases.Optical reflectance of Mg films was measured in near infrared region and larger reflectance was observed from Mg films sputtered in He atmosphere compared to that in argon.

Effect of Texture on Biodegradable Behavior of an As-Extruded Mg–3%Al–1%Zn Alloy in Phosphate Buffer Saline Medium

In this work, the corrosion behavior of two differently oriented surfaces of an as-extruded Mg-3%Al- 1%Zn （AZ31） bar in a simulated body fluid of phosphate buffer saline （PBS） medium was investigated and compared, and the effect of crystallographic texture on corrosion resistance of the alloy was deeply described. The results showed that at the early stage of immersion, a layer of compact and flat film formed easily on surfaces of both oriented samples. With prolonged immersion time, the degradation of formed corrosive films started and their severity was quite sensitive to the composed crystallographic planes of sample surfaces. For the surface containing highly concentrated orientation of {10-10} and {11-20} prism planes, the degradation of formed corrosive film was quite slight and only occurred at some particular sites even after immersion for 48 h. Thus, the film could keep good corrosive protection to the under- neath substrate. However, for the surface containing [0002} basal planes, {10-10} and {11-20} prism planes, the degradation of corrosive production film occurred widely, resulting in further decrease in the corrosion resistance of immersed samples,