Syntheses, Structures, and Properties of Non-Centrosymmetric Quaternary Tellurates BiMTeO₆ (M = Al, Ga)

Abstract

Single crystals of two new metal tellurates Bi MTeO ( M = Al, Ga) with a honeycomb layered structure were obtained by the molten flux method and characterized. The Bi MTeO compounds both crystallize into a non-centrosymmetric trigonal space group of P312 (no. 149) with cell parameters of a = 5.0667(8) Å, c = 4.9920(16) Å and a = 5.107(3) Å, c = 4.932(6) Å, respectively. The non-centrosymmetry of BiAlTeO and BiGaTeO originates from the packing order of the octahedra. In these two structures, TeO octahedra and MO octahedra share edges and form a honeycomb open-framework with [Te MO] layers. The layers of [ MTeO] and [BiO] alternate and are connected along the c-axis by corner-sharing oxygen atoms to form the three-dimensional framework. The chiral compound BiGaTeO exhibits a powder second harmonic generation (SHG) response of ∼0.2 times that of potassium dihydrogen phosphate (KDP) and an absorption edge of 355 nm.

Solid‐state nuclear magnetic resonance of spin‐9/2 nuclei 115In and 209Bi in functional inorganic complex oxides

“…[26,27] The stereochemically active lone pair in Bi 3+ can lead to noncentrosymmetric structures with useful optoelectronic and ferroic properties. [28][29][30][31][32] Given the range of technological applications and frequently cation-mixed and/or poorly diffracting nature of bismuth and indium oxides, it is desirable to develop alternative metrologies to study their atomic environments. 115 In and 209 Bi solid-state nuclear magnetic resonance (NMR) spectroscopy could, in principle, offer additional insights into the local coordination, symmetry, and ionic/polyhedral dynamics.…”

“…[19] BiAlTeO 6 and BiGaTeO 6 are isostructural layered compounds with alternating pure BiO 6 and mixed, ordered MO 6 /TeO 6 (M = Al, Ga) (Figure 1b). [31] Collection of the broad (>15 MHz) NMR spectra is facilitated by signal enhancement from the quadrupolar Carr-Purcell-Meiboom-Gill (QCPMG) pulse sequence in combination with frequency-stepped acquisition, also known as the variable-offset cumulative spectrum (VOCS) [69] approach. The results are described in the context of the very different local symmetry and coordination environments of indium and bismuth in these examples.…”

Solid-State NMR of Spin-9/2 Nuclei 115In and 209Bi in Functional Inorganic Complex Oxides

“…Crystalline samples of LiIn 2 SbO 6 and BiGaTeO 6 were synthesized by high-temperature solid-state methods while BiAlTeO 6 was synthesized from a flux to overcome substantial impurities observed from the previously described method. 31 Laboratory powder XRD confirmed the crystal structure and crystalline purity of each sample. Based on the flux composition, this scattering contribution is attributed to amorphous sodium tellurates.…”

“…80 LiIn 2 SbO 6 , BiAlTeO 6 , and BiGaTeO 6 crystal structures were used as starting models. 19,31 Prior to the NMR calculations, atomic positions and lattice were optimized until the force on any atom was smaller than 1 meV Å −1 . All calculations used a planewave energy cutoff energy of 700 eV and a Monkhorst−Pack 81 grid with a spacing finer than 2π × 0.03 Å −1 to sample the Brillouin zone.…”

Preparation, Structural Analysis, and Tunability of Optical and Dielectric Characteristics of Mn–modified SrLaLiTeO6 Double Perovskite

“…The emergence of medium peaks at 495 cm −1 can be assigned to antisymmetric stretching vibrations (v1) in Te(Li)O6 octahedra. At the same time, strong peaks at 662, 680, 710, and 731 cm −1 can be assigned to the symmetric stretching vibration (v2) of the Te(Li)O6 octahedra[19,[33][34][35][36]. It is clear that as dopant concentration increased, there were more quenched of peaks.…”