Podrobnosti záznamu

Název
    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
Autor
    Comodi, Paola
    Drábek, Milan
    Rieder, Milan
    Weiss, Zdeněk
    Zanazzi, Pier Francesco
Jazyk
    anglicky
Zdrojový dokument - seriál
    American mineralogist
Svazek/č.
    Vol. 84, no. 3
Strany
    p. 325-332
Rok
    1999
Poznámky
    4 diagr., 8 tab., 29 bibl.
    Zkr. název ser.: Amer. Mineralogist
Předmětová skupina
    cesium
    gradient geotermický
    izotopy Cs
    izotopy radioaktivní
    krystalová struktura
    odpad radioaktivní
    slídy
    syntéza minerálu
    vysoká teplota
    vysoký tlak
Klíčové slovo
    Behaviour
    Cs-tetra-ferri-annite
    Disposal
    High-pressure
    High-temperature
    Nuclear
    Phase
    Potential
    Waste
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
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    18. 2. 2008
Datum importu
    8. 8. 2012