Double-Layered Polycrystalline Iron Garnet Structure of Bi3Fe5O12 and Y3Fe5O12 grown on SiO2 substrates by pulsed laser deposition

Abstract

Iron Garnet single crystals like Bi3Fe5O12 are important ceramic systems with extensive applications in structural ceramics and optoelectronics. Currently, it is desirable to integrate such macroscopic components on a single chip (e.g. Si, SiO2, ...) as in the case of microelectronics (integrated optics). High quality magneto-optical active garnet films with high Faraday rotation are also needed for magneto-optical imaging. In our present work we studied the integration of Bi3Fe5O12 on different SiO2 substrates using the pulsed laser deposition method. Therefore we deposited a Y3Fe5O12 buffer first which was optimized in a post-annealing step above 900 °C in order to form a polycrystalline garnet phase, which is needed for further Bi3Fe5O12 growth.We measured the Faraday rotation of the films and intensely studied them with x-ray diffraction, Rutherford Backscattering Spectroscopy, Environmental Scanning Electron Microscopy, X-ray photoelectron spectroscopy and High-Resolution Transmission Electron Microscopy. The attained Faraday rotation can be compared with epitaxial Bi3Fe5O12 films grown on Gd3Ga5O12 substrates.Finally we present an easy solution to generate linear polarized light on the substrate by an organic light emitting diode, which can be coupled into to the garnet thin film.