MgO is an excellent single crystal substrate for thin films of Ferro magnetic, Photo-electronic and high Tc superconductor materials. Across uses a special arc melting method to grow high purity MgO crystal in sizes up to 2”x2”x 1” at lower cost, and employs CMP method to prepare high quality substrates with atomic level smoothness. We also provides MgO substrate with as-cleaved surface. For some applications, as-cleaved MgO substrate gives better epitaxial thin film due to its more favorable surface conditions.