Transition metal and rare earth ions with unfilled 3d and 4f electron shells, respectively, find numerous applications in optical materials, e.g. as active emitting ions in laser crystals and phosphors. In the present work we give an overview of basic electronic and spectroscopic properties of these ions in a free state and in crystal fields of various symmetries [1]. Special attention is paid to the energies of electronic transitions used for getting visible emission for lighting and optical thermometry. The main factors that affect positions of the emission peaks and their intensity are analyzed. Examples of combined calculations of the impurity ions energy levels based on the crystal field theory and ab initio methods are discussed in detail [2-6].

References:

[1] Mikhail G. Brik, Chong-Geng Ma, Theoretical Spectroscopy of Transition Metal and Rare Earth Ions: From Free State to Crystal Field, Jenny Stanford Publishing, Singapore, 2020.

[2] M.G. Brik, S.J. Camardello, A.M. Srivastava, N.M. Avram, A. Suchocki, ECS J. Sol. State Sci. Technol. 5 (2016) R3067-R3077.

[3] M.G. Brik, C.-G. Ma, A.M. Srivastava, M. Piasecki, Chin. J. Lumin. 41 (2020) 1011-1029.

[4] M.G. Brik, W.W. Beers, W. Cohen, S.A. Payne, N.J. Cherepy, M. Piasecki, A.M. Srivastava, Opt. Mater. 91 (2019) 338-343.

[5] M.G. Brik, C.-G. Ma, M. Piasecki, A. Suchocki, Opt. Mater. 113 (2021) 110843.

[6] N.Mironova-Ulmane, M.G. Brik, J. Grube, G. Krieke, M. Kemere, A. Antuzevics, E. Gabrusenoks, V. Skvortsova, E. Elsts, A. Sarakovskis, M. Piasecki, A.I. Popov, Opt. Mater. 132 (2022) 112859.