Abstract: Substituted gadolinium gallium garnet (SGGG) crystal is an important substrate material for liquid-phase epitaxial growth of magneto-optical single crystal thin films. SGGG crystals with uniform structure and stable physical properties are the basis for the preparation of magneto-optical single crystal thin films. This article reports the preparation of four different Ca²⁺/Mg²⁺/Zr⁴⁺ doped gadolinium gallium garnet crystals using the Czochralski method.The X-ray rocking curve test shows that the prepared crystals are high crystallinity without twinning, and full width at half maximum (FWHM) is 2.04′, 2.07′, 1.85′, 1.98′, respectively, the lattice constant is 12.440 4~12.481 8 Å. The number of dislocation density is 53~161 cm^-2. The surface roughness of crystal surface (111) measured by atomic force microscopy (AFM) ranges from 0.123 nm to 0.244 nm. The thermal expansion coefficient of the crystal is 8.27×10^-6~8.64×10^-6. The crystal has good transmittance in the wavelength range of 500~2 500 nm. SGGG crystals prepared by adjusting the doping amount of Ca²⁺/Mg²⁺/Zr⁴⁺ can meet the performance requirements of substrate materials for epitaxial growth of magneto-optical single crystal thin films.

Key words: gadolinium gallium garnet, calcium magnesium zirconium doping, magneto-optic single crystal, substrate material, Czochralski method