GGG, SGGG, and NGG Garnets are used as substrates for liquid phase epitaxy (LPE). GGG substrates are substrates oriented for growing magneto-optical film. GGG substrates are often used to grow the YIG or BIG film placed in a magnetic field, which is an indispensable part of an infrared isolator operating within the 1.3-1.5μm range utilized for optical communication. GGG single crystal substrates of different tangential can achieve the best lattice match with the magneto-optical material, thus ensuring the YIG and BIG film epitaxial growth is successful. SGGG Single-crystal is excellent for growing bismuth-substituted iron garnet epitaxial films.