Podrobnosti záznamu

    Cs-tetra-ferri-annite: High-pressure and high-temperature behaviour of a potential nuclear waste disposal phase
Údaj o odpovědnosti
    Paola Comodi, Pier Francesco Zanazzi, Zdeněk Weiss, Milan Rieder, Milan Drábek = Pier Francesco Zanazzi = Zdeněk Weiss = Milan Rieder = Milan Drábek
    Comodi, Paola
    Drábek, Milan
    Rieder, Milan
    Weiss, Zdeněk
    Zanazzi, Pier Francesco
Zdrojový dokument - seriál
    American mineralogist
    Vol. 84, no. 3
    p. 325-332
    4 diagr., 8 tab., 29 bibl.
    Zkr. název ser.: Amer. Mineralogist
Předmětová skupina
    gradient geotermický
    izotopy Cs
    izotopy radioaktivní
    krystalová struktura
    odpad radioaktivní
    syntéza minerálu
    vysoká teplota
    vysoký tlak
Klíčové slovo
Abstrakt (anglicky)
   Structure deformation induced by pressure and temperature in synthetic "Cs-tetra-ferri-annite" 1M [Cs1.78(Fe2+5.93Fe3+0.07)(Si6.15Fe3+1.80Al0.05)O20(OH)4], space group C2/m, were analyzed to investigate the capability of the mica structure to store the radiogenic isotopes 135Cs and 137Cs. "Cs-tetra-ferri-annite" is not a mineral name, but for the sake of brevity is used here to designate a synthetic analog of the mineral tetra-ferri-annite. The bulk modulus and its pressure derivate determined by fitting the unit-cell volumes between 0 and 47 kbar to a third-order Birch-Murnaghan equation of state are K0=257(8) kbar and K0'=21(1), respectively. Between 23°C and 582°C, the a and b lattice parameters remain essentially unchanged, but the thermal expansion coefficient of the c axis is c=3.12(9)x10-5°C-1. High pressure (P) and high temperature (T) produce limited internal strain in the structure.
   The tetrahedral rotation angle, alpha, is very small and does not change significantly throughout the P and T range investigated. Above 450 °C in air, "Cs-tetra-ferri-annite" underwent an oxidation of octahedral iron in the M2cis site, balanced by the loss of H and shown by decrease of the unit-cell volume. Independent isobaric data on thermal expnasion and isothermal compressibility data define the "geometric" equation of state for "Cs-tetra-ferri-annite": V/V0=1+3.0(1) 10-5T-2.68(9) 10-3P+2.0(2)x10-5P where T is in degrees Celsius, P is in kilobars. The alpha/beta ratio of about 12 kbar /°C indicate that the cell volume of "Cs-tetra-ferri-annite" remains unchanged under geothermal gradients of &23 °C/km. On the whole, the data confirm that the structure of "Cs-tetra-ferri-annite" may be a suitable candidate for the storage of large ions, such as Cs in the interlayer and should be considered as a potential Synroc component
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
Datum vložení
    18. 2. 2008
Datum importu
    8. 8. 2012