Studies on some ternary oxyborates of the Na2O–Me2O3–B2O3 (Me=rare earth or aluminum) systems: synthesis, structure and crystal growth
| hal.structure.identifier | Institute of General and Inorganic Chemistry | |
| dc.contributor.author | PESHEV, Pavel | |
| hal.structure.identifier | Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB] | |
| dc.contributor.author | PECHEV, Stanislav | |
| hal.structure.identifier | Institute of General and Inorganic Chemistry | |
| dc.contributor.author | NIKOLOV, Velin | |
| hal.structure.identifier | Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB] | |
| dc.contributor.author | GRAVEREAU, Pierre | |
| hal.structure.identifier | Institut de Chimie de la Matière Condensée de Bordeaux [ICMCB] | |
| dc.contributor.author | CHAMINADE, Jean-Pierre | |
| hal.structure.identifier | Institute of General and Inorganic Chemistry | |
| dc.contributor.author | BINEV, Daniel | |
| hal.structure.identifier | Institute of General and Inorganic Chemistry | |
| dc.contributor.author | IVANOVA, Diana | |
| dc.date.issued | 2006 | |
| dc.identifier.issn | 0022-4596 | |
| dc.description.abstractEn | Sodium rare-earth oxyborates Na2RE2O(BO3)2 (RE=Y, Nd, Er) were prepared for the first time in the present study. They were found to be isostructural with phases of the same composition containing Sm, Eu or Gd and reported by Corbel et al. [J. Solid State Chem.144 (1999) 35–44]. It was shown that the yttrium and erbium compounds could be synthesized at 900–1000 °C by a solid-state reaction between oxides in an equimolecular ratio. With both oxyborates melting led to decomposition into a mixture of Y(Er)BO3, Y2(Er2)O3 and Na2B4O7. Just the opposite was observed during thermal treatment of the oxide mixture containing Nd2O3, from which a practically pure phase of Na2Nd2O(BO3)2 was only obtained after melting. The attempts to synthesize the oxyborate Na2La2O(BO3)2 showed it to be unstable, this leading to the formation of a mixture containing, in addition to Na2La2O(BO3)2, also other already known stable phases of the system Na2O–La2O3–B2O3 along with an unknown ternary oxide phase. This phase was found to represent a new oxyborate of sodium and lanthanum with the formula Na3La9O3(BO3)8, whose single crystals were obtained by flux growth. It was established that synthesis of a polycrystalline material with the same composition was also possible using solid-state interaction between Na2CO3, La2O3 and H3BO3 at 1000–1100 °C. X-ray diffraction experiments on single crystals were used to solve the structure of Na3La9O3(BO3)8. The unit cell was found to be hexagonal, space group P62m (No. 189) with Z=1. The compound can be regarded as the forefather of a second group of oxyborates representing a new family of isostructural compounds, Na3RE9O3(BO3)8. Such phases were obtained with RE=Nd, Sm and Eu whereas with RE=Y and Gd, the synthesis experiments failed. The concentration and temperature regions of crystallization of the double-oxyborate Na2Al2O(BO3)2 in the ternary system Na2O–Al2O3–B2O3 were determined. This compound was shown to melt incongruently at 970±3 °C, which made high-temperature solution growth most appropriate for obtaining its single crystals with NaBO2 as the best solvent. On the basis of the data obtained, a composition of the initial solution was proposed, the validity of the choice being demonstrated by the growth of Na2Al2O(BO3)2 single crystals on a seed using the top-seeded solution growth (TSSG) technique and slow cooling of the solution. | |
| dc.language.iso | en | |
| dc.publisher | Elsevier | |
| dc.subject.en | Oxyborates | |
| dc.subject.en | Crystal structure | |
| dc.subject.en | Solid-state synthesis | |
| dc.subject.en | Flux growth | |
| dc.subject.en | Rare earths | |
| dc.subject.en | Aluminum | |
| dc.title.en | Studies on some ternary oxyborates of the Na2O–Me2O3–B2O3 (Me=rare earth or aluminum) systems: synthesis, structure and crystal growth | |
| dc.type | Article de revue | |
| dc.identifier.doi | 10.1016/j.jssc.2006.01.027 | |
| dc.subject.hal | Chimie/Matériaux | |
| bordeaux.journal | Journal of Solid State Chemistry | |
| bordeaux.page | 2834-2849 | |
| bordeaux.volume | 179 | |
| bordeaux.issue | 9 | |
| bordeaux.peerReviewed | oui | |
| hal.identifier | hal-00111968 | |
| hal.version | 1 | |
| hal.popular | non | |
| hal.audience | Non spécifiée | |
| hal.origin.link | https://hal.archives-ouvertes.fr//hal-00111968v1 | |
| bordeaux.COinS | ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Journal%20of%20Solid%20State%20Chemistry&rft.date=2006&rft.volume=179&rft.issue=9&rft.spage=2834-2849&rft.epage=2834-2849&rft.eissn=0022-4596&rft.issn=0022-4596&rft.au=PESHEV,%20Pavel&PECHEV,%20Stanislav&NIKOLOV,%20Velin&GRAVEREAU,%20Pierre&CHAMINADE,%20Jean-Pierre&rft.genre=article |
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