A number of oxygen vacancies were found in the MgO film when a nanoscale-metal embedded MgO film (MgO/nanoscale metal film/MgO) was exposed to a pulsed KrF excimer laser. This was due to the interfacial reaction between embedding nanoscale metal and MgO film. In a case of Nb embedding metal, the Nb 2 O 5 crystallites were evidenced to proceed the reaction at the MgO/Nb interface; 5MgO + 2Nb f Nb 2 O 5 + 5Mg + 5V O 3 3 . The oxygen vacancies formed the F centers in the MgO bandgap, resulting in high cathodoluminescence intensity at the 431 and 526 nm region, corresponding to F + and F centers. The F centers in MgO played a role in increasing secondary electron emission coefficient (γ). As several kinds of nanoscale metals for creating F centers (Cr, Ti, V, In, Ta, and Nb) were embedded into MgO film, the γ values were found to be inversely linear with the ΔG f for the formation of metal oxides. The Nb embedded MgO film showed the highest γ value of ∼0.232 compared with normal MgO film (0.034).

Preferred orientation of polycrystalline MgO film changed from (111) to (200) as the deposition rate reduced from 20Å/sec to 3Å/sec. The oxygen vacancies were easily produced at the surface of (200) plane due to low surface cohesive energy. These oxygen vacancies were acted as defect center in the band gap of MgO, resulting in the increase of secondary electron emission coefficient from 0.032 to 0.048.