Electron Spin Resonance Study on Local Structure of Manganese Ions Doped in Gamma-Aluminum Oxynitride Phosphors

摘要

References(12) We have studied the local structure of manganese ion doped in gamma aluminum oxynitride phosphors (γ-AlON: Mn) using electron spin resonance (ESR) experiment. Six sharp peaks appear in ESR spectra of γ-AlON: Mn, together with five weak doublets. These structures are caused by the hyperfine interaction of 3d electrons with the 55Mn nucleus of spin I=5/2. The six peaks are attributed to the allowed transitions (ΔMI=0) between hyperfine splitting states of Ms=±1/2. The five doublets are interpreted as the forbidden transitions (ΔMI=±1) between the hyperfine splitting states. The spectral feature of γ-AlON: Mn resembles with the ESR spectrum of Mn2+ doped MgAl2O4 spinel, in which Mn2+ ions are substituted for tetrahedral Mg2+ sites. Since γ-AlON is also of the spinel structure, it is suggested that Mn2+ ions occupy tetrahedral Al3+ sites. We further chased the effect of Mg2+ co-doping on ESR spectra of Mn2+ ions in γ-AlON, in order to elucidate the luminescence enhancement in γ-AlON: Mn, Mg. It turned out that the Mg2+ co-doping increases Mn2+ ions at tetrahedral Al3+ sites.