Formation of BaMgF4 Films on Pt/MgO, Si and GaAs Substrates

Abstract

AbstractCrystalline quality of BaMgF4 films grown on Pt/MgO, Si, and GaAs substrates either by solid phase crystallization (SPC) or by molecular beam epitaxy (MBE) has been investigated. In the SPC method, the films are deposited typically at 300°C in amorphous state and subsequently crystallized at temperatures higher than 500°C. It has been found from X-ray diffraction analysis that (010)-oriented films are grown on the three substrates by the SPC method, while that (011)- and (120)-oriented films are grown on respective (100)- and (111)-oriented substrates of Si and GaAs, when the MBE method is used at substrate temperatures around 500°C. These results show that the spontaneous polarization which is generated along a-axis of a BaMgF4 crystal, is not parallel to the film surface, only when the films are grown on (111) substrates by MBE.