M. Kizilyalli

X-ray powder diffraction and IR study of NaMg(H2O)2[BP2O8]·H2O and NH4Mg(H2O)2[BP2O8]·H2O

NaMg(H2O)2[BP2O8]·H2O was prepared by hydrothermal synthesis and was characterized by X-ray powder difraction and IR method. The title compound was synthesized from MgCl2·6H2O, NaBO3·4H2O, and (NH4)2HPO4 with variable molar ratios using hydrothermal method by heating at 165 °C for 3 days. The X-ray powder diffraction data was indexed in hexagonal system, the unit cell parameters were found to be as a = 9.428, c = 15.82 Å, Z = 4 and the space group is P6122. It is isostructural with MlMll(H2O)[BP2O8] type compounds where Ml = Na, K; Mll = Mg, Mn, Fe, Co, Ni and Zn. In addition NH4Mg(H2O)2[BP2O8]·H2O was also synthesized the first time in this research. Its unit cell parameters and hkl values were in good agreement with the sodium magnesium compound. The unit cell parameters are a = 9.529, c = 15.736 Å. The indexed X-ray powder diffraction data of both compounds which were not reported in the literature is presented in this work. The IR data of NaMg(H2O)2[BP2O8]·H2O is also reported.

Synthesis of Strontium Borophosphate, SrBPO5 by Solid State and Hydrothermal Methods and Characterisation

SrBPO 5 was synthesized by a solid-state reaction reported and by a new solid state reaction using BPO 4 as a phosphating agent. It was also obtained by a hydrothermal method. The structure of the compound was solved by Rietveld analysis before. The examination of X-ray powder diffraction data showed that, SrBPO 5 is isostructural with CaBPO 5 and BaBPO 5 . It crystallizes in the trigonal system in P3 1 21 and the refined unit cell parameters are a = 6.8488(1), c = 6.8159(2) A, Z=3 and D m 3.77 g/cm 3 .

Solid-State Synthesis, X-ray Powder Investigation and IR Study of α-Mg3[BPO7]

Abstract α-Mg 3 [BPO 7 ] (low temperature form) which is isostructural with Zn 3 [BPO 7 ] has been synthesized by the solid-state reactions of MgHPO 4 .H 2 O with MgCO 3 and H 3 BO 3 at 1200°C, Mg 3 B 2 O 6 with MgCO 3 and (NH 4 ) 2 HPO 4 at 1100°C, and MgO with B 2 O 3 and P 2 O 5 at 1100 with the molar ratios of 1:2:1, 1:3:2 and 6:1:1, respectively. The structure of α-Mg 3 [BPO 7 ] was found to be orthorhombic (as already reported), with refined unit cell parameters of a =8·495(3), b =4·886(1) and c =12·565(4) A; the space group is Immm with Z=4. The indexed X-ray powder diffraction data and the IR spectrum of α-Mg 3 [BPO 7 ] are also given. The latter reveals trigonal planar coordination of boron.

Synthesis of a new orthorhombic metastable form of CdS through solid-state reactions

Abstract CdS has been prepared through solid-gas reactions of CdO with a sulfidizing gas mixture, at 750°C for 3 hr, and slow cooling under nitrogen atmosphere. The X-ray diffraction data of the product was indexed in a hexagonal system with unit cell parameters of a = 4.136 and c = 6.713A, which agreed with the literature data. However, the presence of extra strong lines in the X-ray diffraction pattern and the splitting in the d-spacings showed that a new orthorhombic form of CdS was obtained. The unit cell dimensions were found to be a = 14.315, b = 14.074, and c = 14.568A and the space group was found to be Pnnn. The IR absorption spectrum showed the formation of pure CdS. The X-ray powder pattern of this phase which was taken after 2 years showed only the presence of the hexagonal phase reported in the literature. This proved that the orthorhombic phase is metastable.

Solid-state synthesis and X-ray diffraction studies of Na2S

Abstract Na2S was synthesized by a new solid-gas reaction of Na2CO3 with a sulfidizing gas mixture and a solid-solid reaction of carbon with Na2SO4. The reaction products were analyzed by X-ray powder diffraction and IR methods. Two new crystal modifications of Na2S were identified in addition to the previously reported antifluorite structure. They were designated as cubic Form II and orthorhombic Form III. The approximate unit cell dimensions were found to be a = 11.29 A for the cubic form and a = 15.94, b = 16.00, and c = 16.18 A for the orthorhombic form.