EPR and optical spectroscopy of Cr³⁺ doped CaYAIO₄

Abstract

EPR and optical measurements have been carried out on Cr³⁺ doped CaYAIO₄ at 1.6 K, 16 K and 300 K. Q-band measurements revealed a strong, asymmetric EPR line close to g ≃ 2 for B//c, together with three weak fine-structure lines corresponding to tetragonal symmetry. The R₁ line of Cr³⁺ has an inhomogeneous broadened linewidth of about 100 cm⁻¹ at 16 K but a homogeneous width of less than 10 cm⁻¹, the measurement of which was monochromator slit width limited. The large inhomogeneous broadening of the optical and EPR spectra are attributed to the compositional disorder of Ca²⁺ and Y³⁺ in the host lattice.

Key Words:

• Key words
• transition metal ion
• EPR
• compositional disorder
• fluorescence line narrowing.