| 摘要 |
PROBLEM TO BE SOLVED: To scarcely cause splash and form an MgO film to be formed into an almost uniform thickness even by depositing a vapor by an electron beam vapor deposition method. SOLUTION: This MgO vapor depositing material comprises a sintered compact pellet of a polycrystalline MgO having >=99.90% of MgO purity, especially <=30 ppm content of carbon and >=98% relative density. Furthermore, contents of impurities contained in the sintered compact pellet of the polycrystalline MgO are respectively <=150 ppm each of Si and Al impurities expressed in terms of element concentrations, <=200 ppm of Ca impurity expressed in terms of the element concentration, <=50 ppm of Fe impurity expressed in terms of the element concentration, <=10 ppm each of Cr, V and Ni impurities expressed in terms of the element concentrations, <=20 ppm each of Na and K impurities expressed in terms of the element concentrations and <=150 ppm of Zr impurity expressed in terms of the element concentration. |
