Czochralski growth of Sr2Tb8(SiO4)6O2 crystals for visible–near IR magneto-optical applications

Abstract Sr 2 Tb 8 (SiO 4 ) 6 O 2 crystals have been grown and investigated for the first time for magneto-optical applications. The X-ray powder diffraction confirms that the compound crystallizes in the hexagonal system, with a common oxyapatite structure. The as-grown crystal exhibits low thermal expansion anisotropy ( α a / α c  ≈ 1.1), and the hardness is about 5.0 Moh. The temperature dependence of the magnetic susceptibility indicated that the Sr 2 Tb 8 (SiO 4 ) 6 O 2 crystal exhibits paramagnetic behavior over the experimental temperature-range 2–300 K. The present investigations demonstrate that Sr 2 Tb 8 (SiO 4 ) 6 O 2 crystals show a higher visible transparency and a larger Faraday rotation than terbium gallium garnet (TGG) crystals. Sr 2 Tb 8 (SiO 4 ) 6 O 2 is therefore a very promising material in particular for new magneto-optical applications in the visible–near IR wavelength region.