title: [Spectral properties of broad emission bands of Cr3+ in A3M2Ge3O12 (A = Cd2+, Ca2+; M = AI3+, Ga3+, Sc3+) garnets].
abstract: The spectral properties of the Cr3+ broad emission band in A3M2Ge3O2 : Cr(A = Cd2+ ,Ca3+; M = Al3+,Ga3+,Sc3+) germanate garnets at room temperature are reported for the first time. In the order of Al3+ --> Ga3+ --> Sc3+ and Cd2+ --> C2z+ ions which occupy the octahedral and duodeahedral sites, respectively, R-NIR broad emission band of 4T2 --> 4A2 level transition, emission peak, and the spectral long wavelength and short wavelength sides of Cr3+ shift to long wavelengths having lower energy. The reason is that the crystal field strengths in the octahedral decrease, while the cation ionic radii in the A3M2Ge3O12 system garnets increase gradually. The R-NIR emission intensity of Cr3+ is increased with some Sc3+ ions substitution for Al3+ or Ga3+ ions in octahedral sites.
authors.affiliation: Laboratory of Excited State Processes and Changchun Institute of Physics, Chinese Academy of Sciences, 130021 Changchun.
authors.forename: X
authors.initials: X
authors.lastname: Liu
authors.forename: X
authors.initials: X
authors.lastname: Zhang
authors.forename: L
authors.initials: L
authors.lastname: Huang
authors.forename: J
authors.initials: J
authors.lastname: Yuan