Vibrational spectra and factor group analysis of rare-earth chromium borates, RCr3(BO3)4, with R=La–Ho

Borovikova, E. Yu.; Dobretsova, Elena; Болдырев, К. Н.; Kurazhkovskaya, V. S.; Maltsev, V.; Leonyuk, N. I.

doi:10.1016/j.vibspec.2013.05.004

Cited by 38 publications

(22 citation statements)

References 10 publications

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“…According to a factor‐group analysis the vibrations of B‐O bond in the rare earth orthoborates with the general formula RM 3 (BO 3 ) 4 (R ‐ Nd, Ga, Y; M ‐ Al, Ga, Cr, Fe), which crystallize in rhombohedral and in monoclinic structures, main frequencies of the vibrations of this bond located in a region 1400–570 cm −1 . Hence, bands in the region from 1400 to 1100 cm −1 due to asymmetrical stretching vibrations, 1060–960 cm −1 due to symmetrical stretching vibrations of the B‐O boron triangles, and bands in the range 820 – 570 cm −1 due symmetric and asymmetric deformations of vibration of B‐O bond in the boron triangles.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of two new orthoborates KBaPr(BO₃)₂ and KBaNd(BO₃)₂

Кононова

Шевченко

Кох

et al. 2017

Crystal Research and Technology

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Two new rare-earth orthoborates KBaPr(BO 3 ) 2 and KBaNd(BO 3 ) 2 were synthesized using a two-step solid-state reaction, both of them are stable in the temperature range 850-1000°C. KBaNd(BO 3 ) 2 and KBaPr(BO 3 ) 2 show incongruent melting at 1019°С and 1005°С, respectively. Prepared compounds crystallize in the trigonal system with space group R3m with cell parameters of а = 5.5052(12)Å, с = 18.402(8)Å, Z = 3 for KBaPr(BO 3 ) 2 and cell parameters of а = 5.4956(5)Å, с = 18.278(3)Å, Z = 3 for KBaNd(BO 3 ) 2 . These new borates continue the previously described line of isostructural three-cation orthoborates KBaY(BO 3 ) 2 and KBaR(BO 3 ) 2 , by R = Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu. The identity of the intensity and position of the bands in the IR spectra confirm that these compounds are isostructural and have high degree of homogeneity. A red emission centered at 700-740 nm under UV excitation was observed for synthesized KBaPr(BO 3 ) 2 powder.

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Section: Resultsmentioning

confidence: 99%

Synthesis of two new orthoborates KBaPr(BO₃)₂ and KBaNd(BO₃)₂

Кононова

Шевченко

Кох

et al. 2017

Crystal Research and Technology

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“…In the overwhelming number of cases, the crystal structures (first of all, coordinates of atoms) of the samples were refined by the full-profile Rietveld method on polycrystalline samples obtained by the solid-state reaction (LnFe 3 (BO 3 ) 4 with the Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, (Y), Ho; LnGa 3 (BO 3 ) 4 with the Ln = Sm, Gd, Y, Ho, Er) [34,53] or on single crystals synthesized by the flux method and ground to a powder (LnAl 3 (BO 3 ) 4 with the Ln = Nd, Sm, Eu, Gd, Tb, Dy, (Y), Ho, Er, Yb; LnFe 3 (BO 3 ) 4 with the Ln = Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, (Y), Ho; LnGa 3 (BO 3 ) 4 with the Ln = Gd) [1,54,56,59,61,66,68]. Assignment of a series of rare-earth orthoborates (LnAl 3 (BO 3 ) 4 with the Ln = Nd, Eu, Gd, Tb, Dy, (Y), Ho, Er, Tm, Yb; LnFe 3 (BO 3 ) 4 with the Ln = Eu, Gd, Y; LnCr 3 (BO 3 ) 4 with the Ln = Sm, Eu, Gd, Tb, Dy; LnGa 3 (BO 3 ) 4 with the Ln = Nd, Eu, Gd, (Y), Ho) to the space group R32 is performed on powdered single crystals obtained by the flux method using IR spectroscopy coupled with the group-theoretical analysis [26,42,45,51,70,71,73], temperature-dependent high-resolution optical absorption Fourier spectroscopy and Raman spectroscopy (LnFe 3 (BO 3 ) 4 with the Ln = Pr, Nd) [57,58,60].…”

Section: Methodsmentioning

confidence: 99%

“…IR/S, T s = 143 K [65] R32: D/P [1], D/? [27], IR/S (50:50, 900-950 • C; 70:30, 1040-1050 • C) [70], IR/S (1:1; 1.5:1; 2.3:1) [71], IR/S [26,45] R32: D/? [27], D/P [34,54], IR/P [45] R32: ?…”

Section: Space Groups For Thementioning

confidence: 99%

“…The space group C2/c is known for the LnAl 3 (BO 3 ) 4 with the Ln = Pr, Nd, Sm, Eu, Tb, Ho (the structure is refined, for example, in [97]); LnFe 3 (BO 3 ) 4 with the Ln = Nd; LnCr 3 (BO 3 ) 4 with the Ln = La, Pr, Nd, Sm, Tb, Dy, Ho; LnSc 3 (BO 3 ) 4 with the Ln = La, Ce, Pr ( Table 1). The centrosymmetry was determined by spectroscopic studies using a factor-group analysis of vibrations (for the LnAl 3 (BO 3 ) 4 with the Ln = Pr [42], Nd [42,45]; LnFe 3 (BO 3 ) 4 with the Ln = Nd [45]; LnCr 3 (BO 3 ) 4 with the Ln = La (Figure 10), Pr, Tb, Dy, Ho [70,71], Nd [26,45,70,71], Sm [70,72]). The LnSc 3 (BO 3 ) 4 crystals with the Ln = La, Ce, obtained by the Czochralski method, crystallize in the centrosymmetric space group C2/c), according to a study of their nonlinear optical properties [35].…”

Section: Scmentioning

confidence: 99%

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Crystallochemical Design of Huntite-Family Compounds

et al. 2019

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Huntite-family nominally-pure and activated/co-activated LnM3(BO3)4 (Ln = La–Lu, Y; M = Al, Fe, Cr, Ga, Sc) compounds and their-based solid solutions are promising materials for lasers, nonlinear optics, spintronics, and photonics, which are characterized by multifunctional properties depending on a composition and crystal structure. The purpose of the work is to establish stability regions for the rare-earth orthoborates in crystallochemical coordinates (sizes of Ln and M ions) based on their real compositions and space symmetry depending on thermodynamic, kinetic, and crystallochemical factors. The use of diffraction structural techniques to study single crystals with a detailed analysis of diffraction patterns, refinement of crystallographic site occupancies (real composition), and determination of structure–composition correlations is the most efficient and effective option to achieve the purpose. This approach is applied and shown primarily for the rare-earth scandium borates having interesting structural features compared with the other orthoborates. Visualization of structures allowed to establish features of formation of phases with different compositions, to classify and systematize huntite-family compounds using crystallochemical concepts (structure and superstructure, ordering and disordering, isostructural and isotype compounds) and phenomena (isomorphism, morphotropism, polymorphism, polytypism). Particular attention is paid to methods and conditions for crystal growth, affecting a crystal real composition and symmetry. A critical analysis of literature data made it possible to formulate unsolved problems in materials science of rare-earth orthoborates, mainly scandium borates, which are distinguished by an ability to form internal and substitutional (Ln and Sc atoms), unlimited and limited solid solutions depending on the geometric factor.

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“…Порядковый номер Согласно результатам фактор-группового анализа колебаний связи В-О в редкоземельных ортоборатах с общей формулой RM 3 (BO 3 ) 4 (R -Nd, Ga, Y; M -Al, Ga, Cr, Fe), кристаллизующихся как в ромбоэдрической, так и в моноклинной структурах, основные частоты колебаний этой связи расположены в области волновых чисел 1400-570 см -1 [15][16][17]. Следуя выводам этих работ, мы можем отнести полосы в области от 1400 до 1100 см -1 к валентным асимметричным колебаниям, полосы в области 1060-960 см -1 -к валентным симметричным колебаниям связи В-О борных треугольников, а полосы в области спектра 820 -570 см -1 -к деформационным симметричным и асимметричным колебаниям связи В-О борных треугольников.…”

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