Nitrides and oxynitrides: Preparation, crystal chemistry and properties

Synthesis, Crystal Structure and Optical Properties of LaNbON2

“…Reoxidation studies of LaNbON 2 performed under synthetic air in a thermobalance ( Figure 4) revealed temperature stability up to T = 500 K. Further heating led to the formation of a reoxidation intermediate already observed for other perovskite oxynitrides [24,25]. This intermediate contains nitrogen molecules chemically bonded in a crystal lattice, which basically still retains the perovskite structure but shows a rather low crystallinity [7,20,22]. The presence of nitrogen can be verified for example by Raman spectroscopy or XPS [14].…”

“…Based on its composition, a low optical band gap value and a complex crystal structure can be expected for this material. The preparation of LaNbON 2 by thermal ammonolysis of LaNbO 4 was reported by Marchand et al [22]. According to their preliminary X-ray powder diffraction study the oxynitride crystallizes in a GdFeO 3 -type perovskite structure.…”

Octahedral and trigonal-prismatic coordination preferences in Nb-, Mo-, Ta-, and W-based ABX2 layered oxides, oxynitrides, and nitrides

“…Even though there are potential applications, most of the reported properties include the effects of the surface layers, impurities, and grain connections. For the synthesis of oxynitrides and nitrides, a major approach is to heat (typically above 600-1000 °C) the oxide, sulfide, or chloride precursors under an ammonia flow; in these reactions, the temperature profile and ammonia flow rate should be kinetically controlled [12,[71][72][73]. Single crystals of several ABX2 compounds have been grown using flux methods (LiNbO2 [74,75], CaNb2O4 [47], and NaNbN2 [76]); however, many ABX2 compounds are only available in the powder form.…”

Electronic structure of the alkaline-earth silicon nitrides M2Si5N8(M = Ca and Sr) obtained from first-principles calculations and optical reflectance spectra

“…More and more attention has been paid to nitrides in recent years [1][2][3][4]. Some binary nitrides, such as Si 3 N 4 , AlN and GaN, have been intensively investigated both experimentally and theoretically and are applied in industry [5][6][7].…”