抄録
Chromium magnesium oxynitride (Cr1-x-Mgx-N-O) thin films with x ranging from 0 to 1.0 have been successfully prepared by pulsed laser deposition (PLD) method. The present work is to report oxidation behavior of the Cr1-x-Mgx-N-O thin films. From the results of oxidation tests, oxidation starting temperature of Cr0.52-Mg0.48-N-O thin film was approximately 100°C higher than that of Cr-N-O thin film. Furthermore, MgCr2O4 was formed as oxide phase in the Cr0.52-Mg0.48-N-O thin film above T=800°C. The Cr0.52-Mg0.48-N-O thin film exhibited high hardness above HV=3000 in the range from RT to T=700°C. However, the hardness of Cr0.52-Mg0.48-N-O thin film heat-treated above 800°C including MgCr2O4 phase decreased rapidly. SEM observation also revealed that voids existed in all heat-treated thin films. These voids are thought to be brought by the formation of oxide.