Fabrication and magneto-optic property of infrared transparent gadolinium iron garnet (GdIG) ceramics by hot-press sintering process

A series of GdIG ceramics with good infrared transparency have been fabricated by a hot-press sintering process with vacuum/oxygen atmosphere. The effects of the powder synthesizing temperature and the ceramic sintering temperature on the phase structure and microstructure of the GdIG ceramics were examined and analyzed. The GdIG ceramic sample sintered at 1275 °C from the Gd2O3 and Fe2O3 powders pre-synthesized at 1000 °C demonstrated an exceptionally high infrared transmittance, it is ≥ 68% within the wavelength range of 1500-5000 nm (t=0.5 mm). Furthermore, the magnetic and magneto-optic property of the GdIG ceramic samples were investigated and discussed. When a saturation external magnetic field of ∼50 mT acting on the GdIG ceramic sample, the specific Faraday rotation angles are about 104 deg./cm and 51 deg./cm at 1064 and 1550 nm wavelength respectively. It exhibits a good faraday effect of GdIG ceramics which is rarely reported until now.