Dodecahedral Positions Research Articles

Efficiency of Cr3+ → Cr4+ conversion in YSAG:Cr ceramics

In this study, we investigated the influence of the position and quantitative content of scandium in YSAG:Cr on the efficiency of chromium cation valence conversion. YSAG:Cr ceramic powders were synthesized using the chemical precipitation method. It was determined that the microstructure of ceramics and the luminescent properties of YSAG:Cr4+ depend on the predominant position of scandium, whether it replaces octahedral or dodecahedral positions in the garnet crystal lattice. An increase in Scdod content contributed to a decrease in grain size and a shift of the emission peak of Cr4+ ions towards the short-wavelength region. Conversely, an increase in Scoct content led to an increase in grain size and a shift of the maximum of the luminescent band towards the long-wavelength region. It was found that increasing the quantitative content of scandium in the octahedral position in the garnet structure by up to 50 % enhances the efficiency of the conversion of Cr3+ to Cr4+, while an increase in the proportion of Scdod resulted in a decrease in conversion efficiency.

LA-ICP-MS U-Pb dating, chemical composition and evolution of oscillatory zoned andradite from the Chengmenshan Cu-Au deposit, Jiangxi province

The Chengmenshan Cu-Au deposit is a typical porphyry-skarn deposit in the Middle-Lower Yangtze River Valley Metallogenic Belt (MLYRMB), developing abundant oscillatory zoned andradite. However, the physiochemical conditions, hydrothermal evolution and age of skarn formation is unknown. This paper presents BSE image, EMPA point analyses, LA-ICP-MS point analyses and mapping, U-Pb isotope data for andradite from the Chengmenshan Cu-Au deposit. From core to rim, three generations of andradite could be identified (Grt-1, Grt-2, Grt-3). Grt-1 (Adr73-88) exhibit compositional variations as oscillatory zoning. Grt-2 (Adr93-100) is almost pure andradite, with smooth surface. Grt-3 (And71-93) occur as halo surrounding earlier andradite, with broken surface. Incorporation of REE and U into all generations of andradite mainly follows coupled YAG-type substitution mechanism and the coupled substitution of [U4+]VIII + 2[Fe3+, Al3+]Ⅳ – [Ca2+] – 2[Si4+]Ⅳ in the dodecahedral position, respectively. Their associated intrusions, mineral assemblages and consistent positive Eu anomalies indicate an acidic, oxidizing and low salinity forming conditions. From core to rim, the contents of REE and HFSE are decreasing, and the REE patterns evolve from flatted, through LREE-enriched, HREE-depleted, to REE-depleted. The chemical composition and evolution of oscillatory zoned andradite suggest that the fluids in Chengmenshan deposit experienced the sequences of pore fluid-mixed, through magmatic-hydrothermal dominated, to meteoric water influx. In this process, the temperature, pH and fluid compositions varied. U contents are closely correlated with REE contents, especially LREE contents. The andradite samples yield Tera-Wasserburg lower intercept 206Pb/238U ages of 140.1 ± 2.6 Ma (MSWD = 1.8), representing the age of Cu-Au mineralization. These results indicate the evolutionary characteristics of hydrotheraml fluids and precisely date the Cu-Au skarn formation, which may serve as a useful indicator in the exploration of similar skarn deposits and point selection for U-Pb dating.

Almandine jewelry garnet from the Kitelya deposit (Karelia): composition and spectroscopic properties

Research subject. The chemical composition and spectroscopic properties of almandine jewelry garnets from the Kite-lya deposit in the Northern Ladoga region (Karelia). Materials and methods. The chemical composition, impurity elements, mineral inclusions and spectroscopic properties of almandine jewelry crystals were studied using IR and Mössbauer spectroscopy. Results. Garnet crystals were found to exhibit a weakly pronounced zonal composition, varying from Alm75Pir15Sps7Grs3 in the center to Alm80Pir14Sps4Grs2 at their edges. Therefore, the Ca and Mn contents decrease towards the grain edges. This zonality of garnets is characteristic of the processes of progressive metamorphism of their host rocks. The garnet crystals feature small inclusions of quartz, chlorite, mica FACI (biotite), ilmenite, rutile, monazite, zircon and pyrrhotite. The composition of chlorite, biotite and zircon was established. The parameter of the cube unit cell ao = 11.522 ± 0.003 Å was calculated. The IR absorption spectra of 995, 966, 901, 878, 638, 568, 528, 476 and 455 cm–1 are characteristic of the pyrope-almandine difference. Mössbauer spectroscopy revealed an insignificant admixture of trivalent iron (Fe3+) in the structure of Kitelya garnets (≈1 % of the amount of isomorphic iron). The obtained optical absorption spectra of garnet plates in the visible light spectrum indicate that Fe2+ ions in dodecahedral positions, to a lesser extent dodecahedral Mn2+ ions, as well as possibly octahedral Fe3+ ions are responsible for the bright red-crimson color of pyrop-almandine from the Kitelya deposit. Conclusions. A “portrait” of typomorphic features (composition and properties) of the pyrope-almandine jewelry garnet from the Kitelya deposit was obtained. This portrait can be used when analyzing the historical finds of faceted or cabochonized differences of almandine in jewelry, church utensils in both Russia and Europe (where this jewelry material was exported during the 17th century). The preservation of garnet jewelry differences in the host rock is due to the presence of thin amorphous kelefite shells or soft minerals (sericite, chlorite, kaolinite etc.).

Широкополосная ЭПР-спектроскопия кристалла Lu-=SUB=-3-=/SUB=-Al-=SUB=-5-=/SUB=-O-=SUB=-12-=/SUB=-:Tb-=SUP=-3+-=/SUP=-

In a single crystal of lutetium aluminum garnet (Lu3Al5O12, LuAG) in the frequency range of 37–210 GHz, at a temperature of 4.2 K, the EPR spectra of non-Kramers Tb3+ impurity ions were recorded. The measurement results indicate that Tb3+ ions replace Y3+ ions in the dodecahedral position with local D2 symmetry. The value of the g factor, the hyperfine structure constant, and the energy interval between the ground and the first excited nondegenerate sublevels of the ground multiplet are determined. Weak satellite signals were also registered, the origin of which is associated with the formation of antisite defects in the environment of paramagnetic Tb3+ centers.

Wide-band EPR spectroscopy of a Lu-=SUB=-3-=/SUB=-Al-=SUB=-5-=/SUB=-O-=SUB=-12-=/SUB=-:Tb-=SUP=-3+-=/SUP=- crystal

In a single crystal of lutetium aluminum garnet (Lu3Al5O12, LuAG) in the frequency range of 37-210 GHz, at a temperature of 4.2 K, the EPR spectra of non-Kramers Tb3+ impurity ions were recorded. The measurement results indicate that Tb3+ ions replace Y3+ ions in the dodecahedral position with local D2 symmetry. The value of the g factor, the hyperfine structure constant, and the energy interval between the ground and the first excited nondegenerate sublevels of the ground multiplet are determined. Weak satellite signals were also registered, the origin of which is associated with the formation of antisite defects in the environment of paramagnetic Tb3+ centers. Keywords: hyperfine interaction, rare earth ions, spin Hamiltonian, non-Kramers ion.

Application of EPR Spectroscopy for Investigation of Antisite Defectsin Yttrium-Aluminum Garnet

Paramagnetic Ce3+, Tb3+ and Ho3+ centers in the yttrium position in yttrium aluminum garnet (YAG) crystals investigated by the EPR spectroscopy. Along with the main EPR signals of Ce3+ and non-Kramers Tb3+ ions located in a regular environment a number of new centers with less lines intensity with different g-factors and zero-field splitting observed. The number of lines and the symmetry of these centers indicate that they belong to cerium and terbium ions, near which there are YAl antisite defects (Y3+ in octahedral positions of Al3+) or AlY (Al3+ in dodecahedral positions of Y3+). In addition to the main EPR signals of non-Kramers Ho3+ ions located in Y3+, a number of less intense lines with different parameters also attributed to antisite defects.

Luminescence and photoconversion properties of micro-powder phosphors based on the Ce3+ and Mn2+ doped Ca2YMgScSi3O12 silicate garnets

This work is dedicated to study the synthesis processes and luminescence properties of micro-crystalline powder phosphors of Ce3+ and Mn2+ doped Ca2YMgScSi3O12 garnets (CYMSSG:Ce and CYMSSG:Ce,Mn) The photoluminescence emission spectra and decay kinetics confirm the formation of Ce3+ multicenters in the CYMSSG:Ce powder phosphor due to local inhomogeneity of the different dodecahedral positions and presence of the energy transfer between high-energy and low energy Ce3+ emission centers in this garnet. The effective Ce3+ to Mn2+ energy transfer process is observed in CYMSSG:Ce, Mn phosphors resulting in the redshift of the emission spectra in comparison with CYMSSG:Ce counterpart. We have shown that CYMSSG:Ce and CYMSSG:Ce, Mn powder phosphors can be used as an efficient photoconverter (PC) for creation of the high-power white LEDs (WLEDs). The prototypes of PC-WLEDs, based on 450 nm emitting blue LED and planar layers of CYMSSG:Ce and CYMSSG:Ce, Mn microcrystalline powder phosphors, embedded in the epoxy resin, were prepared and their photoconversion properties were investigated as well.

Evidence of two Yb3+ crystallographic sites occupancy in Y3Al5O12 ceramics from an in depth spectroscopic analysis

In this paper a complete spectroscopic analysis of low-temperature absorption and emission spectra of 10 ​at.% Yb:YAG ceramic are investigated. On the basis of the analysis of the temperature dependences of individual spectral lines (from 10 ​K to 300 ​K), as well of the joint analysis of the Raman spectra and the temperature-resolved absorption and emission spectra a two center model of Yb3+ doping ion is proposed. Namely, most of the ytterbium ions replace yttrium ions in dodecahedral positions (c-site), while a small part replaces yttrium ions in octahedral positions (a-anti-site).

Stable garnets in the Er2O3–Sc2O3–Al2O3 oxide system for optical ceramics application

Erbium-scandium-aluminum garnets (ErSAG) with the maximum possible concentrations of scandium cations in the dodecahedral and octahedral positions of the crystal lattice have been synthesized. It has been established that in ErSAG at a temperature of 1600 °C the maximum possible concentration of scandium in the dodecahedral and octahedral position reaches 64.7 ± 2.0 at. % and 92.0 ± 2.0 at. %, respectively. The maximum possible concentrations of scandium cations in the dodecahedral position and the set of range of possible ErSAG compositions decrease at increasing of calcination temperature. It was shown that ceramics technique allow to produce the optical ceramics with compositions {Er1.5Sc1.5}[Sc0.2Al1.8](Al3)O12 (SAG: Er 50 at%) and {Y1.57Er0.03Sc1.4}[Sc0.2Al1.8](Al3)O12 (YSAG: Er 1 at%), which can be considered as analogs of yttrium-aluminum garnet single crystals (YAG: Er 50 at% and YAG: Er 1 at%).

Micropowder Ca2YMgScSi3O12:Ce Silicate Garnet as an Efficient Light Converter for White LEDs.

This work is dedicated to the crystallization and luminescent properties of a prospective Ca2YMgScSi3O12:Ce (CYMSSG:Ce) micropowder (MP) phosphor converter (pc) for a white light–emitting LED (WLED). The set of MP samples was obtained by conventional solid-phase synthesis using different amounts of B2O3 flux in the 1–5 mole percentage range. The luminescent properties of the CYMSSG:Ce MPs were investigated at different Ce3+ concentrations in the 1–5 atomic percentage range. The formation of several Ce3+ multicenters in the CYMSSG:Ce MPs was detected in the emission and excitation spectra as well as the decay kinetics of the Ce3+ luminescence. The creation of the Ce3+ multicenters in CYMSSG:Ce garnet results from: (i) the substitution by the Ce3+ ions of the heterovalent Ca2+ and Y3+ cations in the dodecahedral position of the garnet host; (ii) the inhomogeneous local environment of the Ce3+ ions when the octahedral positions of the garnet are replaced by heterovalent Mg2+ and Sc3+ cations and the tetrahedral positions are replaced by Si4+ cations. The presence of Ce3+ multicenters significantly enhances the Ce3+ emission band in the red range in comparison with conventional YAG:Ce phosphor. Prototypes of the WLEDs were also created in this work by using CYMSSG:Ce MP films as phosphor converters. Furthermore, the dependence of the photoconversion properties on the layer thickness of the CYMSSG:Ce MP was studied as well. The changes in the MP layer thickness enable the tuning of the white light thons from cold white/daylight to neutral white. The obtained results are encouraging and can be useful for the development of a novel generation of pcs for WLEDs.

Correlations between Garnet Species and Vibration Spectroscopy: Isomorphous Substitution Implications

Garnet has many species because of its common isomorphism. In this study, a suite of 25 natural gem-quality garnets, including pyrope, almandine, spessartine, grossular, and andradite, were examined by standard gemological testing, LA-ICP-MS, FTIR, and Raman analysis. Internal stretching and bending vibrations of the SiO4-tetrahedra of garnet exhibit correlate with the type of cations in garnet’s dodecahedral position (A site) and octahedral position (B site). FTIR and Raman spectra showed that with the increase of the radius of Mg2+, Fe2+, Mn2+, and Ca2+ in A site, or the unit cell volumes of pyrope, almandine, spessartine, and grossular, the spectral peaks of Si–Ostr and Si–Obend modes shift to low wavenumber. Because of the largest cations both in A site (Ca2+) and in B site (Fe3+), andradite exhibited the lowest wavenumber of Si–Ostr and Si–Obend modes of the five garnet species. Therefore, garnet has correlations between chemical composition and vibration spectroscopy, and Raman or IR spectroscopy can be used to precisely identify garnet species.

Wideband EPR spectroscopy of Y-=SUB=-3-=/SUB=-Al-=SUB=-5-=/SUB=-O-=SUB=-12-=/SUB=- : Ho-=SUP=-3+-=/SUP=- crystals

EPR spectra of Ho3+ impurity ions were recorded in single crystals of yttrium aluminum garnet (Y3Al5O12) in the frequency range of 114-170 GHz, at a temperature of 4.2 K. The measurement results indicate the substitution of Ho3+ ions for Y3+ ions in the dodecahedral position with D2 local symmetry. The magnitude of the g-factor, the hyperfine structure constant, and the energy interval between the main and the first excited nondegenerate sublevels of the main multiplet 5I8 are determined. Weak satellite signals have also been registered, the origin of which is associated with the formation of antisite defects in the environment of Ho3+ paramagnetic centers. Keywords: hyperfine interaction, rare earth ions, spin Hamiltonian, non-Kramers ion.

Широкополосная ЭПР-спектроскопия кристалла Y-=SUB=-3-=/SUB=-Al-=SUB=-5-=/SUB=-O-=SUB=-12-=/SUB=-:Ho-=SUP=-3+-=/SUP=-

EPR spectra of Ho3+ impurity ions were recorded in single crystals of yttrium aluminum garnet (Y3Al5O12) in the frequency range of 114-170 GHz, at a temperature of 4.2 K. The measurement results indicate the substitution of Ho3+ ions for Y3+ ions in the dodecahedral position with D2 local symmetry. The magnitude of the g-factor, the hyperfine structure constant, and the energy interval between the main and the first excited nondegenerate sublevels of the main multiplet 5I8 are determined. Weak satellite signals have also been registered, the origin of which is associated with the formation of antisite defects in the environment of Ho3+ paramagnetic centers.

Crystallization and Investigation of the Structural and Optical Properties of Ce3+-Doped Y3−xCaxAl5−ySiyO12 Single Crystalline Film Phosphors

This work is devoted to the crystallization and investigation of the optical properties of single crystalline films (SCFs) of Ce3+-doped Y3−xCaxAl5−ySiyO12 garnet, where the content of Ca2+ and Si4+ cations varied in the x = 0.13–0.52 and y = 0.065–0.5 ranges, respectively. The SCF samples were grown using the liquid phase epitaxy technique onto Y3Al5O12 substrates from the melt solution with equimolar Ca and Si content using PbO-B2O3 flux. However, the Ca and Si concentration in Y3−xCax Al5−ySiyO12:Ce SCFs is not equal: the Ca2+ content was systematically larger than that of Si4+, and the Ca2+ excess is compensated for by the Ce4+ ion formation. The absorption, scintillation, and luminescent properties of Y3−xCaxAl5−ySiyO12:Ce SCFs with different Ca/Si concentrations were investigated and compared with the sample of YAG:Ce SCF. Due to the creation of Ce4+ ions, the as-grown Y3−xCaxAl5−ySiyO12:Ce SCFs show relatively low light yield (LY) under α–particle excitation but a fast scintillation response with a decay time in the ns range. After SCF annealing in the reducing (N2 + H2) atmosphere at T > 1000 °C, the recharging of Ce4+→Ce3+ ions occurs. Furthermore, the samples annealed at 1300 °C SCF possess an LY of about 40% in comparison with the reference YAG:Ce SCF and scintillation decay kinetics much closer to that of the SCF counterpart. Due to Ca2+ and Si4+ alloying, the Ce3+ emission spectra in Y3−xCaxAl5−ySiyO12 SCFs are extended to the red range in comparison with the spectra of YAG:Ce SCF. Such an extension is caused by the Ce3+ multicenter formation at the substitutions of both Y3+ and Ca2+ dodecahedral positions in the hosts of these mixed garnets.

Evidence of the Excitation of Mn2+ Spin-Dependent Photoluminescence in Manganese-Doped Yttrium Aluminum Garnets

Mn2+ ions in yttrium positions have been studied by means of optically detected magnetic resonance (ODMR) via Mn2+ spin-dependent emission in manganese-doped yttrium aluminum garnet crystals. It was shown that the intensity of photoluminescence excited by circularly polarized light depends on the population of the spin sublevels of the Mn2+ ground state and therefore can be used to study the ODMR. EPR measurements have confirmed that Mn2+ ions in the crystals under study occupy preferentially dodecahedral positions in the YAG lattice. Observation of forbidden transitions in the ODMR spectra has proved that the observed ODMR signals belong to Mn2+. Thus the wavelength dependence of the ODMR amplitude reveals the emission band of Mn2+ ions at dodecahedral positions in YAG:Mn.

Combined effect of MgO sintering additive and stoichiometry deviation on YAG crystal lattice defects

Abstract This study aims to investigate the combined effect of the magnesium oxide (MgO) sintering additive and the deviations of the yttrium aluminum garnet (YAG) stoichiometry towards the excess of Al3+ and Y3+ on crystal lattice defects. YAG ceramic powders with an excess of aluminum (up to 4.79 mol.%) or yttrium (up to 2.87 mol.%) and various concentrations of the MgO sintering additive (from 0 to 0.2 wt%) were obtained using a two-stage co-precipitation method. The samples calcined at 1600 °C were studied by X-ray powder diffraction (XRD), scanning electron microscopy, diffuse reflectance, Raman and IR-spectroscopy. The cumulative analysis of theoretical calculations of the composition of the samples was performed based on a change in the lattice parameters. Experimental data obtained suggested that, depending on the YAG stoichiometry, magnesium can substitute both the dodecahedral positions of yttrium (in the case of aluminum excess), as well as the octahedral positions of aluminum (in the case of yttrium excess). The resulting substitution defects give pronounced absorption bands in the diffuse reflectance spectra. An increase in the concentration of introduced magnesium leads to a shift in the IR-transmission maximum of ≈620 cm−1 towards wave numbers increasing with an excess of aluminum and towards wave numbers decreasing with an excess of yttrium. In addition, when magnesium was introduced, a decrease in the intensity of incidental peaks in the Raman spectra was observed, which may be due to the relaxation of stresses due to a decrease in the number of intrinsic crystal lattice defects.

Eu3+ multicenter formation and luminescent properties of Ca3Sc2Si3O12:Eu and Ca2YScMgSiO12:Eu single crystalline films

The work is dedicated to the investigation of Eu3+ multicenter formation and luminescent properties of Ca3Sc2Si3O12:Eu (CSSG:Eu) and Ca2YScMgSiO12:Eu (CYMSSG:Eu) single crystalline film (SCF) phosphors, grown by liquid phase epitaxy method onto Gd3Ga2.5Al2.5O12 (GAGG) and Y3Al5O12 (YAG) substrates, respectively. We have found notable differences in the luminescent properties of CSSG:Eu and CYMSSG:Eu SCFs caused by the Eu3+multicenter formation in both garnets due to the different local surrounding of Eu3+ ions in the dodecahedral positions by the non-isovalent Sc3+/Mg2+ and Si4+ cations in the octahedral and tetrahedral positions of garnet hosts, respectively. A feature of the Eu3+ center creation in CYMSSG:Eu garnet in comparison with CSSG:Eu counterpart is the possibility of localization of Eu3+ ions in dodecahedral sites of both Ca2+ and Y3+ cations. However, based on the obtained results, we have presupposed preferable localization of the Eu3+ ions mainly in the Y3+ positions of this garnet.

Luminescence of Ce3+ multicenters in Ca2+-Mg2+-Si4+ based garnet phosphors

Comparison of the luminescent properties of Ca3Sc2Si3O12:Ce and Ca2YMgScSi3O12:Ce single crystalline films (SCF) phosphors, grown by the liquid phase epitaxy method, was performed in this work. We have observed formation of the Ce3+ multicenters in Ca3Sc2Si3O12:Ce and Ca2YMgScSi3O12:Ce in the emission and excitation spectra as well as in the decay kinetics of the Ce3+ luminescence in SCFs of these garnets. Such Ce3+ multicenters possess different crystal field strength due to the inhomogeneous local surroundings of the dodecahedral positions of garnet host at the substitution of the octahedral positions by hetero-valence Mg2+ and Sc3+ ions and the tetrahedral positions by Si4+ ions. We confirm the presence of an effective energy transfer between different Ce3+ multicenters in Ce3+ doped Ca3Sc2Si3O12 and Ca2YMgScSi3O12 garnets. The positive trends in variations of the spectroscopic properties of the Ca2YMgScSi3O12:Ce garnet with respect to Ca3Sc2Si3O12:Ce garnet were observed also due to substitution of the dodecahedral sites of the garnet host by Y3+ ions and the octahedral sites by Mg2+ ions, which can be suitable for the development of new converters of white LEDs. Namely, due to the Y3+-Mg2+ doping, the luminescence spectrum of Ce3+ ions in Ca2YMgScSi3O12:Ce SCFs significantly extends in the red range in comparison with the Ca3Sc2Si3O12:Ce SCF counterpart.

Luminescent and scintillation properties of Ce3+ doped Ca2RMgScSi3O12 (R = Y, Lu) single crystalline films

The work is dedicated to the growth and investigation of the luminescent and scintillation properties of single crystalline films (SCFs) of Ca2−xR1+xMg1+xSc1−xSi3O12:Ce (R = Y, Lu) mixed garnets with x = 0–0.25, grown using the liquid phase epitaxy method onto Y3Al5O12 substrates from PbO-B2O3 based flux. The absorption, luminescent and scintillation properties of Ca2−xY1+x Mg1+xSc1−xSi3O12:Ce and Ca2−xLu1+xMg1+xSc1−xSi3O12:Ce SCFs with x = 0 and 0.25 were investigated and compared with the reference YAG:Ce and LuAG:Ce SCFs. Using the Ca2+, Mg2+ and Si4+ alloying, the Ce3+ emission spectra in Ca2−xR1+xMg1+xSc1−xSi3O12:Ce (R = Y, Lu; x = 0–0.25) SCFs can be notably extended in the red range in comparison with YAG:Ce and LuAG:Ce SCFs due to the increase of crystal field strength and Ce3+ multicenter creation in the dodecahedral positions of the lattices of these mixed garnet compounds. Due to the formation of Ce4+ ions, the as-grown Ca2−x R1+xMg1+xSc1−xSi3O12:Ce (R = Y, Lu) SCFs at x = 0 and 0.25 show relatively low light yield. However, after annealing in reducing atmosphere (95% N2 + 5% H2) at T > 1000°C, a recharging Ce4+→Ce3+ takes place. After that, these SCFs possess the light yield about of 30% and 31% in comparison with the reference YAG:Ce and LuAG:Ce SCFs, respectively, and a fast scintillation response with the decay times in the ns range under α–particles excitation by 239Pu (5.15MeV) source.

Luminescent and scintillation properties of Lu3Al5O12:Sc single crystal and single crystalline films

The work is dedicated to growth by the liquid phase epitaxy method and study of the luminescence and scintillation properties of Sc3+ doped single crystalline films (SCF) of Lu3Al5O12 (LuAG) garnet. The scintillation properties of SCF are compared with single crystal (SC) analogues grown by the Horizontal Direct Crystallization and Czochralski methods. We consider the dependence of intensity of the Sc3+ emission in LuAG host on the activator concentration and influence of flux contamination on the light yield (LY) of the Sc3+ luminescence in LuAG:Sc SCF with respect to their SC counterparts and the reference YAP:Ce scintillator. From the NMR investigations of LuAG:Sc SCF we confirm the substitution by Sc3+ ions both the octahedral and dodecahedral positions of LuAG host and formation of the ScAl and ScLu related emission centers, respectively. We also show that the luminescence spectrum in the UV range and decay kinetics of LuAG:Sc SCF can be effectively tuned by changing the scandium content.