Metastable States and Physical Properties of Boron-rich W-B films

Abstract

The experimental data on the ion-plasma (13.56 MHz) magnetron sputtering of composite targets of the system W-B are presented. Application of this method allows one to obtain deposited alloys in the entire concentration range of compositions. The as-deposited films show the formation of an amorphous solid state. The decomposition of an amorphous state is accompanied by precipitation of an intermediate metastable, nanocrystalline W-phase with FCC-structure. By applying magnetron sputtering, we have obtained an amorphous state in pure W-films at room temperature. The thermal stability, electrical and mechanical properties of metastable states in W-B films are studied. The study shows that the amorphous state in the WB5 alloy is characterized by abnormally high temperature stability and microhardness. The ion-plasma sputtering method has demonstrated its effectiveness in the case of tungsten films, showing the possibility of obtaining metastable phases in them. At the same time, the obtained values of microhardness in the amorphous alloy turned out to be lower than the predicted maximum theoretical values due to the peculiarities of the location of atoms in the alloy.