MgAl_2O_4 is expected as a suitable protecting material for Transmissive and Reflective Phosphor Type ac-Plasma Displays, because MgAl_2O_4 has transmissive property for ultra violet rays. We analyzed thin film MgAl_2O_4 and MgO by using AES and XPS. AES analysis clarifies oxygen defects in the vacuum evaporated thin films of MgO and MgAl_2O_4. XPS analysis shows the difference in the peak of Mg2p between MgAl_2O_4 and MgO.
