TY  - JOUR
AU  - Mironova-Ulmane, Nina
AU  - Brik, Mikhail G.
AU  - Grube, Jurgis
AU  - Krieke, Guna
AU  - Kemere, Meldra
AU  - Antuzevics, Andris
AU  - Gabrusenoks, E.
AU  - Skvortsova, Vera N.
AU  - Elsts, Edgars
AU  - Sarakovskis, Anatolijs
AU  - Piasecki, Michal
AU  - Popov, Anatoli I.
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10397
AB  - The optical spectra of a single crystal of α-Al2O3Cr3+ were studied in a wide temperature range. The crystal was demonstrated to have a potential for optical thermometric applications. Three ways of measuring temperature were tested and analyzed: i) luminescence intensity ratio of the R1 and R2 lines; ii) change of the full width of half maxima of the R1 and R2 lines, and iii) thermal shifts of the R1 and R2 lines maxima. The highest absolute and relative sensitivities were obtained at cryogenic temperatures. In addition, the thermal shifts of the R lines were analyzed using the McCumber-Sturge equation to estimate the Debye temperature and the electron-vibrational interaction parameter.
T2  - Optical Materials
T1  - EPR, optical and thermometric studies of Cr3+ ions in the α-Al2O3 synthetic single crystal
VL  - 132
SP  - 112859
DO  - 10.1016/j.optmat.2022.112859
ER  - 

@article{
author = "Mironova-Ulmane, Nina and Brik, Mikhail G. and Grube, Jurgis and Krieke, Guna and Kemere, Meldra and Antuzevics, Andris and Gabrusenoks, E. and Skvortsova, Vera N. and Elsts, Edgars and Sarakovskis, Anatolijs and Piasecki, Michal and Popov, Anatoli I.",
year = "2022",
abstract = "The optical spectra of a single crystal of α-Al2O3Cr3+ were studied in a wide temperature range. The crystal was demonstrated to have a potential for optical thermometric applications. Three ways of measuring temperature were tested and analyzed: i) luminescence intensity ratio of the R1 and R2 lines; ii) change of the full width of half maxima of the R1 and R2 lines, and iii) thermal shifts of the R1 and R2 lines maxima. The highest absolute and relative sensitivities were obtained at cryogenic temperatures. In addition, the thermal shifts of the R lines were analyzed using the McCumber-Sturge equation to estimate the Debye temperature and the electron-vibrational interaction parameter.",
journal = "Optical Materials",
title = "EPR, optical and thermometric studies of Cr3+ ions in the α-Al2O3 synthetic single crystal",
volume = "132",
pages = "112859",
doi = "10.1016/j.optmat.2022.112859"
}

Mironova-Ulmane, N., Brik, M. G., Grube, J., Krieke, G., Kemere, M., Antuzevics, A., Gabrusenoks, E., Skvortsova, V. N., Elsts, E., Sarakovskis, A., Piasecki, M.,& Popov, A. I.. (2022). EPR, optical and thermometric studies of Cr3+ ions in the α-Al2O3 synthetic single crystal. in Optical Materials, 132, 112859.
https://doi.org/10.1016/j.optmat.2022.112859

Mironova-Ulmane N, Brik MG, Grube J, Krieke G, Kemere M, Antuzevics A, Gabrusenoks E, Skvortsova VN, Elsts E, Sarakovskis A, Piasecki M, Popov AI. EPR, optical and thermometric studies of Cr3+ ions in the α-Al2O3 synthetic single crystal. in Optical Materials. 2022;132:112859.
doi:10.1016/j.optmat.2022.112859 .

Mironova-Ulmane, Nina, Brik, Mikhail G., Grube, Jurgis, Krieke, Guna, Kemere, Meldra, Antuzevics, Andris, Gabrusenoks, E., Skvortsova, Vera N., Elsts, Edgars, Sarakovskis, Anatolijs, Piasecki, Michal, Popov, Anatoli I., "EPR, optical and thermometric studies of Cr3+ ions in the α-Al2O3 synthetic single crystal" in Optical Materials, 132 (2022):112859,
https://doi.org/10.1016/j.optmat.2022.112859 . .

TY  - JOUR
AU  - Andreici Etimie, E. L.
AU  - Avram, Nicolae M.
AU  - Brik, Mikhail G.
PY  - 2022
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/10452
AB  - The normal spinels (Mg, Zn)Al2O4 doped with transition metal (TM) ions Cr3+/Co2+ are versatile materials with important electronic, optical and spectral properties. In addition to being used in many applications, they are excellent systems for testing some models and simulation features. The aim of this paper is to present, in the unified frame, the results on d-d transitions and ligand field parameters (LFPs) for the title systems, based on ab initio calculations, combining periodic density functional theory (DFT) supercell approach with ab initio (AI) multi -reference perturbation theory (MRPT) and multi-reference configuration interaction (MRCI) methods. These AI methods, based on complete active space self-consistent-field (CASSCF) reference, allow to calculate and investigate the energy levels of TM ions and the d-d transitions between them. From the AI results the B and C Racah parameters, the spin-orbit coupling (SOC) constant and the LFPs in the frame of the angular overlap model (AOM) were accurately extracted with ab initio ligand field theory (AILFT) protocol, all with subsequent comparison with the experimental data or existing theoretical results in the literature. The calculation technique presented in this paper serves as a predictive formalism for further studies of larger monomer clusters, for which experimental data is unreliable or unavailable.
T2  - Optical Materials: X
T1  - The d-d transitions and ligand field parameters for Cr3+/Co2+ doped (Mg, Zn)Al2O4: Multi-reference Ab initio investigations
VL  - 16
SP  - 100188
DO  - 10.1016/j.omx.2022.100188
ER  - 

@article{
author = "Andreici Etimie, E. L. and Avram, Nicolae M. and Brik, Mikhail G.",
year = "2022",
abstract = "The normal spinels (Mg, Zn)Al2O4 doped with transition metal (TM) ions Cr3+/Co2+ are versatile materials with important electronic, optical and spectral properties. In addition to being used in many applications, they are excellent systems for testing some models and simulation features. The aim of this paper is to present, in the unified frame, the results on d-d transitions and ligand field parameters (LFPs) for the title systems, based on ab initio calculations, combining periodic density functional theory (DFT) supercell approach with ab initio (AI) multi -reference perturbation theory (MRPT) and multi-reference configuration interaction (MRCI) methods. These AI methods, based on complete active space self-consistent-field (CASSCF) reference, allow to calculate and investigate the energy levels of TM ions and the d-d transitions between them. From the AI results the B and C Racah parameters, the spin-orbit coupling (SOC) constant and the LFPs in the frame of the angular overlap model (AOM) were accurately extracted with ab initio ligand field theory (AILFT) protocol, all with subsequent comparison with the experimental data or existing theoretical results in the literature. The calculation technique presented in this paper serves as a predictive formalism for further studies of larger monomer clusters, for which experimental data is unreliable or unavailable.",
journal = "Optical Materials: X",
title = "The d-d transitions and ligand field parameters for Cr3+/Co2+ doped (Mg, Zn)Al2O4: Multi-reference Ab initio investigations",
volume = "16",
pages = "100188",
doi = "10.1016/j.omx.2022.100188"
}

Andreici Etimie, E. L., Avram, N. M.,& Brik, M. G.. (2022). The d-d transitions and ligand field parameters for Cr3+/Co2+ doped (Mg, Zn)Al2O4: Multi-reference Ab initio investigations. in Optical Materials: X, 16, 100188.
https://doi.org/10.1016/j.omx.2022.100188

Andreici Etimie EL, Avram NM, Brik MG. The d-d transitions and ligand field parameters for Cr3+/Co2+ doped (Mg, Zn)Al2O4: Multi-reference Ab initio investigations. in Optical Materials: X. 2022;16:100188.
doi:10.1016/j.omx.2022.100188 .

Andreici Etimie, E. L., Avram, Nicolae M., Brik, Mikhail G., "The d-d transitions and ligand field parameters for Cr3+/Co2+ doped (Mg, Zn)Al2O4: Multi-reference Ab initio investigations" in Optical Materials: X, 16 (2022):100188,
https://doi.org/10.1016/j.omx.2022.100188 . .