一般注記Dichroic infrared (IR) absorption measurements on CN~ or OH~ centers in cadmium halide crystals were carried out at 6 K with a high spectral resolution of 0.025 cm-1 at 2000 cm-1, by using a FT-IR spectrometer. Several sharp absorption lines with widths less than 0.1 cm-1 are observed in the energy region of the stretching vibration, i.e. 2000–2250 cm-1 for CN~ and 2500–4500 cm-1 for OH~. These lines are classified into three groups attributed to: (1) an isolated center simply substituted for a halogen ion, (2) an interstitial center located between the cadmium and halogen ion sheets and (3) a coupled center with an anion vacancy. A doublet structure is observed in CdI2 which comes from different halogen-ion sites in the 4H-polytype crystal. The isolated CN~ centers in CdCl2 and CdBr2 align toward Cd2+ ions, away from the direction of the c-axis. Almost all of the coupled center with a vacancy lies in a halogen-ion plane. The doublet structure of the coupled center in CdCl2 and CdBr2 is connected to the tunneling splitting of a vibrational level.
関連情報(DOI)10.1016/j.jlumin.2004.01.014
連携機関・データベース国立情報学研究所 : 学術機関リポジトリデータベース(IRDB)(機関リポジトリ)