Magnetic Field Effect on the Triplet Relaxed Excited States Responsible for the A_T and A_X Emission Bands of Ga⁺ and In⁺ Centers in Alkali Halides

抄録

Degree of circular polarization (DCP) and intensity of the A_T and A_X emission bands in KI : Ga⁺, KBr : Ga⁺, KI : In⁺, KBr : In⁺, and KCl : In⁺ have been investigated at various temperatures (1.4–4.6 K) and field strengths (0–42 kG). The results concerning the A_T band have been qualitatively explained by correlating its relaxed excited state (RES) with the nearly tetragonal minima on the Γ₄⁻ (A) adiabatic potential energy surface (APES) and the three tetragonal minima on the Γ₁⁻ APES. As to a comparison between the A_T and A_X bands, they bear similarities in a particular impurity (Ga⁺ or In⁺); with a decrease of temperature, for example, both the bands show an increase in the DCP of Ga⁺ and show a decrease in the DCP of In⁺. The similarities have prompted us to adopt the recent proposal that the A_X RES consists of the nearly trigonal minima on the Γ₄⁻ (A) APES and the four trigonal minima on the Γ₁⁻ APES.