IR spectroscopy of rare-earth aluminum borates RAl3(BO3)4 (R = Y, Pr-Yb)

Crystal growth, structure, infrared spectroscopy, and luminescent properties of rare-earth gallium borates RGa3(BO3)4, R=Nd, Sm–Er, Y

“…This band is a characteristic feature of the IR spectra of RE borates RAl 3 (BO 3 ) 4 and RCr 3 (BO 3 ) 4 with space group C2/c (C 6 2h ) [15,16]. The region of symmetrical stretching vibrations (v 1 ) of BO 3 3À units in the spectra of NdGa 3 (BO3) 4 and EuGa 3 (BO3) 4 also contains one additional band ($950 cm À1 ) typical for the monoclinic modification.…”

“…8, Table 3). By analogy with aluminum borates [15], these bands were assigned to translations of the RE cations. The bands shift to lower wavenumbers when moving from Y (m = 88.9) to Nd (m = 144.2), 104 ?…”

“…A limiting case of a total structural disorder is described in [10], with diffuse strips along c ⁄ on Weissenberg photos of quenched NdAl-borate samples. The latest spectroscopic investigations have shown that, usually, the structure of RE aluminum [15] or chromium [16] borates is predominantly ordered in one of general types (R32 or C2/c) but often it contains a number of different polytype layers. A pure rhombohedral noncentrosymmetric R32 phase possesses the widest range of useful properties, including nonlinear optical, piezoelectric, and magnetoelectric ones.…”

Structure and Properties of the Non‐Centrosymmetric Manganese(II) Borate Mn5(BO3)3OH

“…Figure shows the single‐crystal FT‐IR spectrum of Mn 5 (BO 3 ) 3 OH in the range from 600 to 4000 cm –1 . The assignment of the modes is based on previous works, investigating borates containing trigonal planar BO 3 groups . In the fingerprint region, the deformation and out‐of‐plane bending vibrations from the trigonal planar BO 3 groups can be found ranging from 600 to 800 cm –1 .…”

Crystallochemical Design of Huntite-Family Compounds

“…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].…”