Structure cristalline de l'orthophosphate monoacide de strontium:SrHPO₄α: forme triclinique

X-Ray Absorption Spectroscopy of Strontium(II) Coordination

“…i SrHPO 4 (s): Boujada et al (30). There are 2 positions for Sr in SrHPO 4 (s), with Sr-Z for each site given by the R pairs.…”

“…Two different structure determinations have been published (26,27) which give slight differences in calculated Sr-Z interatomic distances ( Table 2). The structure of α-SrHPO 4 (s) is triclinic with 8-coordinated strontium in two different crystallographic sites, giving rise to a total of 16 unique Sr-O distances from 2.446 to 3.074Å (Table 2) (30). Despite the large static disorder, the EXAFS spectra could be fit well for both compounds at low and room temperatures as a single first-coordination shell of oxygen atoms: R Sr-O = 2.62Å for SrCO 3 (s) and R Sr-O = 2.57-2.58Å for α-SrHPO 4 (s) ( Table 2 and Fig.…”

Analysis of the effects of thermal treatments on CaHPO4 by 31P NMR spectroscopy

“…For the recorded spectrum, a contact time of 1 ms and a period between successive accumulations of 2 s were chosen. The number of scans was 32832 ( Table 1) (8) where O(6)· · ·O(8) = 2.669(1)Å, is the normal range but is presumed to be statistically disordered with hydrogen covalently bonded to half of the O(6) atoms on the average [4,5]. Table 2, scatters and continuous line correspond to the calculated and the experimental data, respectively; the dotted lines represent the Lorentzian peaks.…”

“…More recently, it has been investigated as protonic conductors [2,3]. The structures consist of CaHPO 4 chains bonded together by Ca · · · O bonds and three types of hydrogen bonds [4,5]. Ca(1) is coordinated to seven oxygen atoms in an approximately pentagonal bipyramid but Ca(2) is coordinated to eight oxygen atoms.…”

1H NMR, 31P NMR and Raman Study of CaHPO4 and SrHPO4

“…All the X-ray peaks 0932-0784 / 05 / 0100-0121 $ 06.00 c 2005 Verlag der Zeitschrift für Naturforschung, Tübingen · http://znaturforsch.com were indexed in the triclinic system with space group P1 indicating a single phase corresponding to the anhydrous form: a = 6.91 (1) 3 for SrHPO 4 (Fig. 1).…”