Startseite Low-temperature behavior of NaGaSi2O6
Artikel
Lizenziert
Nicht lizenziert Erfordert eine Authentifizierung

Low-temperature behavior of NaGaSi2O6

  • F. Nestola EMAIL logo , N. Rotiroti , M. Bruno , M. Tribaudino , S. van Smaalen , H. Ohashi und G .J. Redhammer
Veröffentlicht/Copyright: 1. April 2015
Veröffentlichen auch Sie bei De Gruyter Brill

Abstract

Synthetic NaGaSi2O6-pyroxene, space group C2/c, was investigated at low temperature between 295 to 110 K by X-ray diffraction. The evolution of the unit-cell parameters as a function of temperature does not indicate any structural phase transition down to 110 K. Calculated values for the Debye temperature, θD, and the Grüneisen parameter, γ, are 653(39) and 0.84(8) K, respectively, close to those of other pyroxenes. Five complete intensity data collections were performed at 295, 235, 190, 145, and 110 K to investigate the temperature dependence of the crystal structure. The space group remains C2/c down to 110 K, but anomalies were found between 235 and 190 K for the temperature dependencies of the volume and strain of the M1 polyhedron. This anomalous behavior could be related to variations of the Ga-O2(C1,D1) bond length and the O1(A1,B1)-Ga-O2(C1,D1) bond angle. The C2/c-P1̅ phase transition observed in a previous work for NaTiSi2O6 at about 200 K did not occur for NaGaSi2O6 down to the minimum temperature investigated in this work. This is not due to the different ionic radius at M1 site or to a different tetrahedral chain extension between these two compositions but it is likely due to unfilled t2g orbitals, which do not exist in NaGaSi2O6.

Received: 2006-5-9
Accepted: 2006-10-23
Published Online: 2015-4-1
Published in Print: 2007-4-1

© 2015 by Walter de Gruyter Berlin/Boston

Artikel in diesem Heft

  1. New constraints on metamorphic history of Adirondack diopsides (New York, U.S.A.): Al and δ18O profiles
  2. Hammadah al Hamra 193: The first amphibole-bearing winonaite
  3. Crystal chemistry of trioctahedral micas in alkaline and subalkaline volcanic rocks: A case study from Mt. Sassetto (Tolfa district, Latium, central Italy)
  4. Magnetic excitations and heat capacity of fayalite, Fe2SiO4
  5. The barometer tremolite + tschermakite + 2 albite = 2 pargasite + 8 quartz: Constraints from experimental data at unit silica activity, with application to garnet-free natural assemblages
  6. In-situ measurement of dissolution of anorthite in Na-Cl-OH solutions at 22 °C using phase-shift interferometry
  7. Experimental investigation of the breakdown of dolomite in rock cores at 100 MPa, 650-750 °C
  8. Dissolution of the (001) surface of galena: An in situ assessment of surface speciation by fluid-cell micro-Raman spectroscopy
  9. An infrared spectroscopic study of the OH stretching frequencies of talc and 10-Å phase to 10 GPa
  10. Co2+-Cu2+ substitution in bieberite solid-solution series, (Co1-xCux)SO4·7H2O, 0.00 ≤ x ≤ 0.46: Synthesis, single-crystal structure analysis, and optical spectroscopy
  11. Clinoenstatite exsolution in diopsidic augite of Dabieshan: Garnet peridotite from depth of 300 km
  12. Heat-pulse calorimetry measurements on natural chlorite-group minerals
  13. Low-temperature behavior of NaGaSi2O6
  14. Single-crystal elasticity of zoisite Ca2Al3Si3O12(OH) by Brillouin scattering
  15. The effect of valence state and site geometry on Ti L3,2 and O K electron energy-loss spectra of TixOy phases
  16. Characterization of defects and the local structure in natural and synthetic alunite (K, Na, H3O)Al3(SO4)2(OH)6 by multi-nuclear solid-state NMR spectroscopy
  17. Using a mineral lifetime diagram to evaluate the persistence of olivine on Mars
  18. Complexity in 15- and 30-sectors polygonal serpentine: Longitudinal sections, intrasector stacking faults and XRPD satellites
  19. Light-induced alteration of arsenic sulfides: A new product with an orthorhombic crystal structure
  20. Transmission electron microscopy study of magnetites in a freshwater population of magnetotactic bacteria
  21. Anomalous behavior at the I2/a to Imab phase transition in SiO2-moganite: An analysis using hard-mode Raman spectroscopy
  22. The system Ag-Au-Se: Phase relations below 405 K and determination of standard thermodynamic properties of selenides by solid-state galvanic cell technique
  23. Rhombohedral (9R) and hexagonal (6H) perovskites in barium silicates under high pressure
  24. Structural effects of pressure on monoclinic chlorite: A single-crystal study
  25. Neptunium incorporation in sodium-substituted metaschoepite
  26. The effect of H2O on olivine crystallization in MORB: Experimental calibration at 200 MPa
  27. Symmetry and crystal structure of biaxial elbaite-liddicoatite tourmaline from the Transbaikalia region, Russia
  28. Letter: Onion morphology and microstructure of polyhedral serpentine
  29. Letter: Ion microprobe analysis of (231Pa)/(235U) and an appraisal of protactinium partitioning in igneous zircon
  30. Letter: Structural investigation of Mg local environments in silicate glasses by ultra-high field 25Mg 3QMAS NMR spectroscopy
  31. Letter: Entropies of mixing and subsolidus phase relations of forsterite–fayalite (Mg2SiO4–Fe2SiO4) solid solution
Heruntergeladen am 24.9.2025 von https://www.degruyterbrill.com/document/doi/10.2138/am.2007.2304/html
Button zum nach oben scrollen