Interrelation of the equation of state of MgO and self diffusion coefficients

Abstract

Here, we show that elastic and expansivity data can successfully reproduce the self diffusion coefficients of O and Mg in MgO from a single measurement, through a thermodynamic model that interrelates point defect parameters and bulk properties. The calculated self diffusion coefficients at pressure and temperature conditions prevailing in the lower earth’s mantle, although they cover a wide range of values (i.e., 20 orders of magnitude), compare favorably well with experimental Dexper ones when errors are considered.

Modeling H, Na, and K diffusion in plagioclase feldspar by relating point defect parameters to bulk properties

“…where f is a geometric factor, a is the jump distance equal to the lattice constant (Dologlou 2011;Vallianatos and Saltas 2014), ν is the jump frequency in the order of the Debye frequency ν D (Varotsos and Alexopoulos 1986;Varotsos 2007a), and k B is the Boltzmann constant.…”

“…Notably, a thermodynamic model (termed as the cBΩ model), proposed by Varotsos (1977) and Varotsos and Alexopoulos (1977a, b, 1980a, 1986, Varotsos et al (1978), has been applied to the calculation of defect parameters over a broad range of materials, such as metals, diamond, noble gas solids, fluorides, superionic solids, and viscous liquids (Varotsos and Alexopoulos 1977a, b, 1980b, c, d, 1982, 1986Varotsos et al 1985;Varotsos 2007aVarotsos , b, c, 2008Papathanassiou and Sakellis 2010;Chroneos and Vovk 2015). Recently, its validity has been extended to self-or heterodiffusion in Earth materials (Alexopoulos and Varotsos 1981;Dologlou 2011;Zhang et al 2010Zhang et al , 2011Zhang and Wu 2013;Zhang 2012Zhang , 2014Vallianatos and Saltas 2014;Zhang and Shan 2015a, b;Chroneos and Vovk 2015;Ganniari-Papageorgiou et al 2015;Saltas and Vallianatos 2015). In the present work, our goal is to examine whether the diffusion behaviors of hydrogen and alkali ions in plagioclase feldspars can be reproduced in terms of the bulk and expansivity data based on the recent PVT equation of state of plagioclase feldspars investigated by in situ X-ray diffraction (Angel 2004;Benusa et al 2005;Hovis et al 2010;Tribaudino et al 2010Tribaudino et al , 2011.…”

Germanium diffusion in aluminium: connection between point defect parameters with bulk properties

“…In the single experimental measurement method the calculated value of will be affected on the errors in the preexponential factor, B, Ω, and D1 values, and these can be significant when a single experimental values set is considered. To validate the present results and avoid the dependence of on the experimental uncertainties the mean value method is also considered here [38][39][40][41][42][43]. As mentioned previously the linear behaviour of …”

“…As discussed in previous studies the method of the single experimental measurement (refer to [14,15] and references therein) is not unique and methods such as the so-called compensation law [38,39] and the "mean value" method (MV) [40][41][42] have been used to calculate . In the single experimental measurement method the calculated value of will be affected on the errors in the preexponential factor, B, Ω, and D1 values, and these can be significant when a single experimental values set is considered.…”

Thermodynamic estimation the compressibility of ferropericlase under high pressure

“…This model has been successfully applied to calculate point-defect processes as well as self-diffusion and hetero-diffusion parameters within a wide range of materials, [18][19][20][21][22][23][24][25][26] and in various minerals with geophysical applications. [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] When this relation is differentiated with respect to pressure…”