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The exploration of transition metal oxynitrides has garnered significant interest due to their intriguing property diversity. Herein, we present a promising new transition metal oxynitride BaLa5V2O3N7, which features an anti-perovskite structure type. This unique structural configuration endows the material with remarkable conductivity, particularly at low temperatures, paving the way for the material to be used in a wide range of technological applications. [ABSTRACT FROM AUTHOR]

The new oxonitridosilicates Ln4−xSr2+xSi5N12−xOx (Ln = La, Ce) were synthesized by high temperature solid-state reactions. The crystal structures were solved and refined from both single-crystal and powder X-ray diffraction data. These oxonitridosilicate compounds crystallize in the monoclinic space group P21/n (no. 14) and exhibit a double-layer structure made up of corner-sharing Si(O/N)4 tetrahedra. When excited with near-UV and blue light, the Pr3+ doped La2.31Sr3.69Si5N10.31O1.69 phosphor shows a narrow-band red emission peaking at 625 nm with a full width at half-maximum of 40 nm. [ABSTRACT FROM AUTHOR]

Lead-free [(K0.458Na0.542)0.96Li0.04] (Nb1-xTax)O3 ceramics were prepared by ordinary sintering technique. The effects of Ta content on the phase transitional behavior, Raman spectrum, microstructure, and dielectric, piezoelectric, and ferroelectric properties of the ceramics were investigated. X-ray diffraction results indicate that the phase structure undergoes a transition from orthorhombic to tetragonal phase with the increase in x. The small and large peaks observed in the Raman spectra can all be attributed to the internal modes of the NbO6 octahedron, and both ν5 and ν1 modes slightly shift to lower frequency numbers by increasing x. Ta substitution for Nb leads to the disappearance of the abnormal grain growth behavior, inhibits the grain growth, and improves the density of the ceramics. Increasing x leads to the different variations of dielectric constants before and after poling and makes the ceramics more relaxorlike. The proper substitution of Ta shifts the polymorphic phase transition (at To-T) to near room temperature, and a coexistence of orthorhombic and tetragonal phases is formed, which leads to significant enhancements of the electrical properties. For the ceramics with x=0.15, the electrical properties become optimum, which are as follows: piezoelectric coefficient d33=298 pC/N, electromechanical coupling coefficient kp=0.52, dielectric constant [variant_greek_epsilon]r=1195, dielectric loss tan δ=0.016, To-T=35 °C, Curie temperature TC=366 °C, remanent polarization Pr=28.68 μC/cm2, and coercive field Ec=7.14 kV/cm. These properties are much higher than those of previously reported (K,Na,Li)(Nb,Ta)O3 systems with K:Na=1:1. [ABSTRACT FROM AUTHOR]

A narrow-band blue emitting phosphor Ca8Mg7Si9N22:Eu2+ was synthesized by a high temperature solid state reaction. Ca8Mg7Si9N22 crystallizes in a tetragonal space group P42/nmc (No. 137) with a unit cell of a = 7.3469(6) Å and c = 10.3298(8) Å. The structure framework is composed of [SiN4] tetrahedra and a distorted square-pyramid [MgN5] polyhedron. Under UV light excitation, Ca8−xMg7Si9N22:xEu2+ phosphors exhibit a narrow band emission peaking at 400 nm with a full width at half maximum ∼34 nm. The CIE coordinates of Ca7.95Mg7Si9N22:0.05Eu2+ are (0.1850, 0.0430) with a color purity of 89.22%. More importantly, the Ca8Mg7Si9N22:Eu2+ phosphor shows a remarkably high thermal quenching resistance, maintaining 92% photoluminescence emission intensity at 420 K and 75% at 700 K. Thus Eu2+ doped Ca8Mg7Si9N22 would be a promising blue phosphor even working under considerably high temperature (＞700 K) conditions. [ABSTRACT FROM AUTHOR]

We report a novel narrow-band blue emitting phosphor Sr7.92Mg7Si9N22:0.08Eu2+. The crystal structure of Sr8Mg7Si9N22 is composed of corner-sharing and edge-sharing [SiN4] tetrahedra and distorted square-pyramid [MgN5] polyhedra. Under 350 nm excitation, Eu2+ doped Sr8Mg7Si9N22 emits narrow-band blue light with maximum intensity at 450 nm and a fwhm of 38 nm. [ABSTRACT FROM AUTHOR]

A novel zeolite-like topology oxonitridosilicate La 3.6 Ba 1.7 Si 5 N 10 O 2.1 with the space group Amm 2 (no. 38) and lattice parameters a = 9.5193 (3) Å, b = 16.7011 (5) Å, c = 26.0279 (8) Å, and Z = 12 has been synthesized by a high-temperature solid-state reaction. The crystal structure of La 3.6 Ba 1.7 Si 5 N 10 O 2.1 has four different kinds of tiling, and the cages in the structure are filled with La, Ba, and O atoms. The presence of a noncentrosymmetric space group further suggests its potential for nonlinear optical (NLO) applications, and La 3.6 Ba 1.7 Si 5 N 10 O 2.1 demonstrated a stronger second-harmonic generation (SHG) response than that of SiO 2 .

The exploration of transition metal oxynitrides has garnered significant interest due to their intriguing property diversity. Herein, we present a promising new transition metal oxynitride BaLa 5 V 2 O 3 N 7 , which features an anti-perovskite structure type. This unique structural configuration endows the material with remarkable conductivity, particularly at low temperatures, paving the way for the material to be used in a wide range of technological applications.

Flux synthesis is an effective method to discover large crystals of new compounds. In this paper, a solid-state reaction in Li flux produced a new nitridolithosilicate La 4 Ba 3 Li 3 Si 9 N 19 in the orthorhombic space group Cmcm (No. 63) with lattice parameters of a = 9.7263(1), b = 18.2746(2), c = 11.2929(1) Å, and Z = 4. The La 4 Ba 3 Li 3 Si 9 N 19 exhibits a 3-D framework based on triangular clusters (3-rings) formed by vertex-sharing SiN 4 tetrahedra. The rare earth Pr 3+ -doped La 4 Ba 3 Li 3 Si 9 N 19 emits a narrow-band red emission peaking at approximately 640 nm with a full width at half-maximum of 50 nm when excited under ultraviolet light.

The new oxonitridosilicates Ln 4-x Sr 2+x Si 5 N 12-x O x (Ln = La, Ce) were synthesized by high temperature solid-state reactions. The crystal structures were solved and refined from both single-crystal and powder X-ray diffraction data. These oxonitridosilicate compounds crystallize in the monoclinic space group P2 1 /n (no. 14) and exhibit a double-layer structure made up of corner-sharing Si(O/N) 4 tetrahedra. When excited with near-UV and blue light, the Pr 3+ doped La 2.31 Sr 3.69 Si 5 N 10.31 O 1.69 phosphor shows a narrow-band red emission peaking at 625 nm with a full width at half-maximum of 40 nm.

We report a novel narrow-band blue emitting phosphor Sr7.92Mg7Si9N22:0.08Eu2+. The crystal structure of Sr8Mg7Si9N22 is composed of corner-sharing and edge-sharing [SiN4] tetrahedra and distorted square-pyramid [MgN5] polyhedra. Under 350 nm excitation, Eu2+ doped Sr8Mg7Si9N22 emits narrow-band blue light with maximum intensity at 450 nm and a fwhm of 38 nm.