High-temperature diffusion doping as a method of fabrication of Ca3(VO4)2:Mn single crystals

• Published in: Journal of crystal growth Vol. 563; p. 126104
• Main Authors: Voronina, I.S., Dunaeva, E.E., Papashvili, A.G., Iskhakova, L.D., Doroshenko, M.E., Ivleva, L.I.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.06.2021; Elsevier BV
• Subjects: A1. Diffusion doping; A1. High-temperature annealing; A1. Optical properties; Absorption spectra; Annealing; B1. Calcium orthovanadate; B1. Manganese ions; Crystal growth; Diffusion; Diffusion coefficient; Doped crystals; Doping; High temperature; Manganese ions; Single crystals; Solid phases; A1. High-temperature annealing; A1. Optical properties; B1. Calcium orthovanadate; B1. Manganese ions; A1. Diffusion doping
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2021.126104

•Diffusion doped CVO:Mn crystals were obtained for the first time.•Diffusion coefficients of Mn ions in CVO were calculated for different conditions.•Mn ions in valance states 2+, 3+, 5+ were observed in diffusion doped crystal.•Absorption and luminescence data were obtained for diffusion doped CVO:Mn materials. Calcium orthovanadate Ca3(VO4)2 crystals doped with manganese ions have been fabricated by high-temperature diffusion doping. Nominally pure CVO plates were prepared from the Czochralski grown single crystal. They were used as an effective matrix for diffusion impurity ions from solid phase (Mn2O3 powder) to solid phase (CVO single crystal). The high-temperature diffusion conditions were optimized to obtain the doped crystals of optical quality under using open and closed annealing zones. Diffusion coefficients of manganese ions were calculated for different conditions (temperature interval 1150–1300 °C, annealing time 24 h, 48 h, directions [001], [100]) of diffusion doping of CVO samples. The diffusion coefficient D varied from (3.7 ± 0.6) · 10−8 cm2s−1 at 1150 C up to (1.3 ± 0.2) · 10−7 cm2s−1 at 1300 C. The diffusion activation energy was determined to be 1.7 ± 0.4 eV and 3.3 ± 0.4 eV for the processes based on Fick’s laws during [100] and [001] direction, respectively. The ultimate solubility of manganese in CVO crystals at T = 1300 °C was 3 · 1020 cm−3. The absorption spectrum of diffusion doped Ca3(VO4)2:Mn samples is characterized by a combination of absorption bands specific for Mn2+, Mn3+ and Mn5+ ions. It was indicated that Mn5+ concentration in the diffusion doped CVO:Mn is higher than in CZ-grown Mn-doped materials.