Nano-heterogeneous structure of (1-x)KNbO3–xSiO2 glasses in the low glass-forming oxide content range 0.05 ≤ x ≤ 0.3

Сигаев, В. Н.; Lotarev, S. V.; Ryzhenkov, V. S.; Golubev, N. V.; Stefanovich, S. Yu.; Champagnon, B.; Vouagner, D.; Nardou, Eric; Porcar, Lionel; Палеари, А.; Fargin, Evelyne; Rodriguez, Vincent; Dussauze, Marc

doi:10.1016/j.jnoncrysol.2011.05.004

Cited by 2 publications

(4 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The discovery of rippite also highlights some problems in the synthesis and growth of high-quality crystals suitable for industrial purposes. It is known that synthetic analog of rippite is a good material for nonlinear optics [3][4][5][6][7][8][9][10][11][12][13][14]. Ideal and large single crystals of KNbSi 2 O 7 (near 1 cm) of high optical quality, which are valid for industrial purpose, are still rarity [14].…”

Section: X-ray Crystallography and Crystal Structure Of Rippitementioning

confidence: 99%

“…It is rather inert and chemically stable and is not dissolved in inorganic acids except HF. All studies on KNbSi 2 O 7 are mainly focused on its nonlinear optical property [3][4][5][6][7][8][9][10][11][12][13][14][15]. Single crystals, ceramics, glass-ceramics, and glass of KNbSi 2 O 7 and similar compositions in the systems SiO 2 (±GeO 2 )-Nb 2 O 5 -K 2 O have been fabricated [3][4][5][6][7][8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

“…All studies on KNbSi 2 O 7 are mainly focused on its nonlinear optical property [3][4][5][6][7][8][9][10][11][12][13][14][15]. Single crystals, ceramics, glass-ceramics, and glass of KNbSi 2 O 7 and similar compositions in the systems SiO 2 (±GeO 2 )-Nb 2 O 5 -K 2 O have been fabricated [3][4][5][6][7][8][9][10][11][12]. The synthesis of glasses and glass-ceramics in the system SiO 2 -Nb 2 O 5 -K 2 O has shown that K 2 Nb 2 (Si 4 O 12 )O 2 may be appeared in the 510-735 • C temperature range in glass/melt [4,6,[8][9][10]13,14].…”

Section: Introductionmentioning

confidence: 99%

“…Single crystals, ceramics, glass-ceramics, and glass of KNbSi 2 O 7 and similar compositions in the systems SiO 2 (±GeO 2 )-Nb 2 O 5 -K 2 O have been fabricated [3][4][5][6][7][8][9][10][11][12]. The synthesis of glasses and glass-ceramics in the system SiO 2 -Nb 2 O 5 -K 2 O has shown that K 2 Nb 2 (Si 4 O 12 )O 2 may be appeared in the 510-735 • C temperature range in glass/melt [4,6,[8][9][10]13,14]. The KNbSi 2 O 7 phase has very high optical nonlinearity with its second harmonic generation (SHG) signal greater than that for α-quartz [14,15].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Rippite, K2(Nb,Ti)2(Si4O12)O(O,F), a New K-Nb-Cyclosilicate from Chuktukon Carbonatite Massif, Chadobets Upland, Krasnoyarsk Territory, Russia

et al. 2020

View full text Add to dashboard Cite

Rippite K2(Nb,Ti)2(Si4O12)(O,F)2, a new K-Nb-cyclosilicate, has been discovered in calciocarbonatites from the Chuktukon massif (Chadobets upland, SW Siberian Platform, Krasnoyarsk Territory, Russia). It was found in a primary mineral assemblage, which also includes calcite, fluorcalciopyrochlore, tainiolite, fluorapatite, fluorite, Nb-rich rutile, olekminskite, K-feldspar, Fe-Mn–dolomite and quartz. Goethite, francolite (Sr-rich carbonate–fluorapatite) and psilomelane (romanèchite ± hollandite) aggregates as well as barite, monazite-(Ce), parisite-(Ce), synchysite-(Ce) and Sr-Ba-Pb-rich keno-/hydropyrochlore are related to a stage of metasomatic (hydrothermal) alteration of carbonatites. The calcite–dolomite coexistence assumes crystallization temperature near 837 °C for the primary carbonatite paragenesis. Rippite is tetragonal: P4bm, a = 8.73885(16), c = 8.1277(2) Å, V = 620.69(2) Å3, Z = 2. It is closely identical in the structure and cell parameters to synthetic K2Nb2(Si4O12)O2 (or KNbSi2O7). Similar to synthetic phase, the mineral has nonlinear properties. Some optical and physical properties for rippite are: colorless; Mohs’ hardness—4–5; cleavage—(001) very perfect, (100) perfect to distinct; density (meas.)—3.17(2) g/cm3; density (calc.)—3.198 g/cm3; optically uniaxial (+); ω = 1.737-1.739; ε = 1.747 (589 nm). The empirical formula of the holotype rippite (mean of 120 analyses) is K2(Nb1.90Ti0.09Zr0.01)[Si4O12](O1.78OH0.12F0.10). Majority of rippite prismatic crystals are weakly zoned and show Ti-poor composition K2(Nb1.93Ti0.05Zr0.02)[Si4O12](O1.93F0.07). Raman and IR spectroscopy, and SIMS data indicate very low H2O content (0.09–0.23 wt %). Some grains may contain an outermost zone, which is enriched in Ti (+Zr) and F, up to K2(Nb1.67Ti0.32Zr0.01)[Si4O12](O1.67F0.33). It strongly suggests the incorporation of (Ti,Zr) and F in the structure of rippite via the isomorphism Nb5+ + O2− → (Ti,Zr)4+ + F1−. The content of a hypothetical end-member K2Ti2[Si4O12]F2 may be up to 17 mol. %. Rippite represents a new structural type among [Si4O12]-cyclosilicates because of specific type of connection of the octahedral chains and [Si4O12]8− rings. In structural and chemical aspects it seems to be in close with the labuntsovite-supergroup minerals, namely with vuoriyarvite-(K), K2(Nb,Ti)2(Si4O12)(O,OH)2∙4H2O.

show abstract