Modification of calcium orthovanadate single crystal due to cobalt doping

Voronina, I.S.; Dunaeva, E.E.; Papashvili, A.G.; Doroshenko, Maxim E.; Ивлева, Л. И.

doi:10.1016/j.jcrysgro.2023.127242

Cited by 4 publications

(4 citation statements)

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“…Specifically, absorption lines peaking at about 740 and 1400 nm exhibit the most noticeable difference in relative intensity, with approximately a two‐fold change. In a previous study, [ 13 ] the significant increase in the absorption intensity in the visible and near‐IR region for the diffusion doped crystal was attributed to the presence of Co ions in the 2+ valence state, whereas the absorption increase in the 570 nm region in the crystal doped during synthesis (as shown in Figure 2a) was attributed to the presence of Co 3+ ions.…”

Section: Resultsmentioning

confidence: 86%

“…It should be mentioned that an attempt to obtain a similar cobalt concentration in the crystal doped during the synthesis resulted in a drastic decrease in the resulting optical quality. [ 13 ]…”

Section: Resultsmentioning

confidence: 99%

“…[ 11 ] The growing process and conditions of diffusion annealing for the crystals studied in this article were extensively described before. [ 13 ] The effective cobalt segregation coefficient in Ca 3 (VO 4 ) 2 :Co doped during synthesis did not exceed 0.15. Both samples had good optical quality and were prepared in the form of plates about 3 mm thick.…”

Section: Samples and Equipmentmentioning

confidence: 99%

“…[ 11 ] Previous studies have demonstrated that cobalt ions can occupy tetrahedral and/or octahedral positions within the Ca 3 (VO 4 ) 2 crystal lattice, resulting in changes in the formal charge, ranging from two plus to three plus. [ 12,13 ] Co 2+ ions in different crystals are known to be effective saturable absorbers for passive Q‐switches of 1300–1600 nm lasers. [ 14,15 ] Thus, their spectroscopic properties in calcium orthovanadate crystal are of specific interest.…”

Section: Introductionmentioning

confidence: 99%

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Spectroscopic Properties of Cobalt Ions in Ca₃(VO₄)₂ Crystals Doped via Thermal Diffusion and During Synthesis

Doroshenko,

Ivleva,

Papashvili

et al. 2024

Physica Status Solidi (a)

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The spectroscopic properties of cobalt ions in Ca3(VO4)2 crystals doped via thermal diffusion and during synthesis are investigated. The diffusion doped crystal shows the potential for higher cobalt doping while maintaining its high initial optical quality. The redistribution of several absorption and fluorescence lines intensities with cobalt concentration is attributed to the formation of Co2+ optical centers with sufficiently different local environments. The fluorescence decay times of Co2+ optical centers are measured to differ by an order of magnitude (95 and 13 μs) and are attributed to centrosymmetric M1 and low symmetry M2 types of Co2+ optical centers, possibly corresponding to Ca(4) and Ca(1) positions of Ca3(VO4)2 crystal, respectively. Nonlinear transmission of Co2+ M2 centers is measured, and efficient absorption cross‐sections of 1.4 × 10−19 and 2.4 × 10−19 cm2 are evaluated at 1300 and 1500 nm, respectively. The narrow fluorescence line of cobalt ions peaking at about 1170 nm, detected in both Ca3(VO4)2 crystals doped via thermal diffusion and during synthesis, is attributed to Co ions in a trivalent state.

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Section: Resultsmentioning

confidence: 86%

Section: Resultsmentioning

confidence: 99%

Section: Samples and Equipmentmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Spectroscopic Properties of Cobalt Ions in Ca₃(VO₄)₂ Crystals Doped via Thermal Diffusion and During Synthesis

Doroshenko,

Ivleva,

Papashvili

et al. 2024

Physica Status Solidi (a)

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Crystal structures of biocompatible Mg-, Zn-, and Co-whitlockites synthesized via one-step hydrothermal reaction

Stefanovich,

Lazoryak,

Antipin

et al. 2023

Zeitschrift Für Kristallographie - Crystalline Materials

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Large-scale single crystals of Ca9Mg(PO4)6(PO3OH), Ca9Zn(PO4)6(PO3OH), and Ca9Co(PO4)6(PO3OH) were synthesized using hydrothermal technique, and turned out to be similar to natural bone whitlockite. The hexagonal single crystals about 1 mm with high-quality were obtained with this method for the first time. The crystals were of sufficiently good quality for the precision X-ray structural investigation. The compounds crystallize in usual for this structural type trigonal space group R3c. Presence of hydrogen atom in the structure was confirmed by means of infra-red (IR) spectroscopy, differential scanning calorimetry (DSC) and differential thermogravimetry (DTG) methods. Based on the analysis of the local bond valence sum (BVS), a conclusion on the localization of H atoms was made. The formation of O–H groups and hydrogen bonds H⋯O in vicinity of PO4 tetrahedra was shown and similar to bone whitlockite. This research provides new data on possibility of using hydrothermal technique for obtaining doped bone whitlockites. Hydrogen-containing doped whitlockites can combine bioactive properties and improve biocompatibility due to similarity to natural bond. New structural data are useful for finding the ways to better biocompatibility of whitlockite-based materials.

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Investigation of the cobalt ions diffusion processes in calcium orthovanadate crystals

Voronina,

Dunaeva,

Ivleva

et al. 2023

Izv. vysš. učebn. zaved., Mater. èlektron. teh.

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In this work, the high-temperature diffusion doping method was used for introduction of active cobalt ions into calcium orthovanadate Ca3(VO4)2crystals. Experimental samples were made from a nominally pure CVO single crystal obtained by the Czochralski method. The high-temperature diffusion conditions have been optimized to obtain doped crystals of optical quality during annealing in open and closed zones. Diffusion coefficients of cobalt ions (D) were calculated for various conditions: annealing time 24 - 48 hours; temperature range 1150-1300°C; diffusants - oxide compounds of calcium, cobalt and vanadium: Co3O4, Ca10Co0.5(VO4)7 and Ca3(VO4)2:2wt.%Co3O4; diffusion direction is parallel or perpendicular to the CVO crystal optical axis. The calculated values of the diffusion coefficient varied between 2.09·10-8—1.58·10-7 cm2/s. The activation energy of the diffusion process was determined to be 2.58±0.5 and 2.63±0.5 eV for the [001] and [100] directions, respectively. The maximum cobalt concentration in doped CVO crystals was 2·1020 cm–3. The absorption spectrum of diffusion-doped Ca3(VO4)2:Co samples demonstrates the presence of absorption bands characteristic for Co2+ and Co3+ ions. It was shown that the intensity ratio of the characteristic absorption bands varies depending on the crystal doping method. The optical anisotropy of the crystal increases with dopant concentration increase.

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Modification of calcium orthovanadate single crystal due to cobalt doping

Cited by 4 publications

References 20 publications

Spectroscopic Properties of Cobalt Ions in Ca₃(VO₄)₂ Crystals Doped via Thermal Diffusion and During Synthesis

Spectroscopic Properties of Cobalt Ions in Ca₃(VO₄)₂ Crystals Doped via Thermal Diffusion and During Synthesis

Crystal structures of biocompatible Mg-, Zn-, and Co-whitlockites synthesized via one-step hydrothermal reaction

Investigation of the cobalt ions diffusion processes in calcium orthovanadate crystals

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Modification of calcium orthovanadate single crystal due to cobalt doping

Cited by 4 publications

References 20 publications

Spectroscopic Properties of Cobalt Ions in Ca3(VO4)2 Crystals Doped via Thermal Diffusion and During Synthesis

Spectroscopic Properties of Cobalt Ions in Ca3(VO4)2 Crystals Doped via Thermal Diffusion and During Synthesis

Crystal structures of biocompatible Mg-, Zn-, and Co-whitlockites synthesized via one-step hydrothermal reaction

Investigation of the cobalt ions diffusion processes in calcium orthovanadate crystals

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Spectroscopic Properties of Cobalt Ions in Ca₃(VO₄)₂ Crystals Doped via Thermal Diffusion and During Synthesis

Spectroscopic Properties of Cobalt Ions in Ca₃(VO₄)₂ Crystals Doped via Thermal Diffusion and During Synthesis