Prediction of amorphous phase formation by thermodynamic and kinetic analysis, a Fe-based thin film metallic glass deposited by direct current magnetron sputtering

In- this paper, the Miedema's model and atomic size mismatch (delta factor) were expanded for prediction (Thermodynamic and kinetic analysis) of amorphous structure of an Fe-based thin film system and followed by experimental verification. The Fe44Cr15Mo14Co7 C10B5Si5 thin film metallic glass (TFMG) on P-type Si (100) wafer substrate was deposited by a direct current (DC) magnetron sputtering process with an alloy target derived via spark plasma sintering. In addition, phase and microstructural evolutions of TFMG were studied through x-ray Diffraction (XRD), Grazing Incidence x-ray Diffraction (GIXRD), Atomic Force Microscopy (AFM), Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy equipped with Selected Area Electron Diffraction (TEM-SAED) analysis. The enthalpy, Gibbs free energy changes and the delta factor of the alloy thin film were calculated to be -429.73 kJ.mole(-1), -433.81 kJ.mole(-1) and 16.2, respectively. It can be found that through the Extended Miedema's model and the delta factor, the amorphous structure for the above TFMG could be achieved. Results of XRD and TEM-SAED analysis showed that the TFMG with an amorphous structure was formed. Smooth and uniform surface with low surface roughness of 1.74 nm was detected by FE-SEM and AFM analysis, respectively.