Preparation and Faraday effect of EuS microcrystal-embedded oxide thin films

Abstract

EuS microcrystal-embedded SiO[2], Al[2]O[3], and TiO[2] thin films have been prepared by using rf sputtering method. X-ray diffraction analysis indicates that EuS microcrystal is precipitated as a single phase in Al[2]O[3] and TiO[2] films while precipitation of EuS is not detected in SiO2 film. Faraday effect attributable to the 4f[7]–4f[6]5d transition of Eu[2+] in EuS microcrystalline phase is observed in Al[2]O[3] and TiO[2] films. In particular, Faraday rotation angle observed for EuS-embedded TiO[2] film is large; for instance, the magnitude of Verdet constant for as-deposited TiO[2] film prepared without heating of substrate during the sputtering is 0.15 deg/cm Oe at wavelength of 700 nm. This value is larger by two orders of magnitude than those of Eu[2+]- or Tb[3+]-containing oxide glasses which show the largest Faraday rotation angle among rare-earth-containing glasses, and is comparable to the value for EuSe single crystal.