Characterisation of Pulsed Laser Deposited Bi Doped Dy Iron Garnet Thin Films on GGG(111), GGG(110), YSZ(100) and Si(100)

Abstract
Bi and Ga substituted Dy iron garnet films (~350 nm thick) have been pulsed laser deposited on single crystalline GGG(111), GGG(110), YSZ (100) and Si (100) substrates at a background pressure of 0.1 mbar and substrate temperature in the range of 550-590 °C. Epitaxial growth was obtained only in the case of GGG substrates. Growth on the other substrates resulted in randomly oriented polycrystalline layers. However, in all cases the films exhibited perpendicular anisotropy and Kerr blue spectra of comparable magnitude. The magnetic anisotropy was explained in terms of in plane tensile stress induced by the difference in thermal expansion coefficients between substrate and film. The magneto-optical (MO) behaviour in the 250-900 nm wavelength range, on the first three substrates was consistent with theoretical calculations based on the fundamental constants of BI:YIG thick films grown by LPE. MO studies for growth on Si suggested the presence of interfacial layers introduced by chemical reactions at the film/substrate interface.