High-resolution spectroscopy of Pr3+ions in YAl3(BO3)4:Pr3+. Crystal-field, hyperfine, and electron-deformation interactions

Optical transmission spectra of YAl3(BO3)4 crystals doped with the Pr3+ ions in concentrations 1 and 2.5 at. % were studied by high-resolution (up to 0.05 cm􀀀 1) Fourier spectroscopy, including in magnetic field parallel to the trigonal c axis of the crystal. The g-factors of several crystal-field doublets of Pr3+ were determined. The crystal-field calculations performed using the exchange-charge model and high-resolution spectroscopy data allowed us to obtain a physically reasonable set of crystal-field parameters. The observed splitting of a number of doublets in zero magnetic field is explained by the presence of random lattice deformations. Simulation of the profiles of observed deformational doublets was carried out, taking into account both hyperfine and electrondeformation interactions. The width of the distribution function of random strains was estimated. The main sources of random strains in YAl3(BO3)4:Pr3+ crystals are discussed.