Structural and mechanical properties of amorphous AlMgB14 thin films deposited by DC magnetron sputtering on Si, Al2O3 and MgO substrates

Abstract AlMgB14 coatings have been deposited by DC magnetron sputtering from elemental targets on Si (001), Al2O3 (0001) and MgO (001) substrates at temperatures in the range of 25–350 °C. The structural and mechanical properties of AlMgB14 films were characterized by X-ray diffraction, scanning electron microscopy, nanoindentation, and analyzed as a function of deposition conditions and substrate materials. The results show that all films are X-ray amorphous, and the mechanical properties of the deposited films depend on the substrate and growth temperature. AlMgB14 thin films deposited at 350 °C are found to have smoother surfaces and containing more well-formed B12 icosahedra than the films deposited at lower temperature, which consequently increase the hardness of the deposited films. The maximum hardness and Young’s modulus of the as-deposited films are about 32.3 GPa and 310 GPa, respectively, for films deposited on Al2O3 substrate at 350 °C.