| abstract |
(57) [Summary] Even if a film is formed by an electron beam evaporation method, there is no trouble in a supply system of a MgO sintered body, a splash is not generated, and a stable and uniform film can be formed. The deposited Mg The film characteristics of the O film can be improved. An MgO matrix having a relative density of 95% or more and having crystal grains having an average crystal grain size of 0.3 to 100 μm contains 0.5 alkaline earth metal oxide particles in an MgO matrix. ~ 50% by volume. The alkaline earth metal element in the alkaline earth metal oxide particles is C It is preferable to use one or more elements selected from the group consisting of a, Sr and Ba. |