Zero phonon transitions and interacting Jahn-Teller phonon energies from the fluorescence spectrum of α-Al2O3:Ti3+

Abstract

α‐Al₂O₃:Ti³⁺ (300 ppm) at 10 K shows a broad fluorescence spectrum peaked at 14 380 cm⁻¹ with a progression of small shoulders on the high energy side. At 16 216.1 and 16 178.3 cm⁻¹ are two sharp zero phonon transitions from the Jahn‐Teller distorted ²E_g to B_3/2 and E_1/2, respectively, of the ground term ²T_2g. Two E_g phonons interacting with the ground term ²T_2g have been found with the energies of 220 and 257 cm⁻¹ for interaction with the ground state B_3/2 and of 219 and 256 cm⁻¹ for that with the first excited state E_1/2. The E_g phonon interacting with the excited ²E_g electronic state has an energy of 160 ± 10 cm⁻¹. The Jahn‐Teller stabilization energy of the ²E_g state is estimated to be 3000 cm⁻¹.