Thermodynamics of Point Defects in Solids and Relation with the Bulk Properties: Recent Results

Abstract

For several decades, the crucial question has arisen as to whether there exists any direct interconnection between the thermodynamic parameters of point defects in solids with the bulk properties of the solid under investigation. To answer this important question, an interrelation of the defect Gibbs energy gi in solids with bulk properties has been proposed almost half a century ago. Considering that gi corresponds to an isobaric and isothermal process, this interrelation states that, for different processes (defect formation, self-diffusion activation, and heterodiffusion), gi is proportional to the isothermal bulk modulus B and the mean volume per atom Ω, termed cBΩ model. Here, we review several challenging applications of this interrelation that appeared during the last decade (2011–2021), including high pressure diamond anvil measurements, high Tc superconductors, nuclear fuels, and materials for micro-electronics devices, applications of usefulness in Geophysics and Seismology, a problem of major technological interest, search for compositions of better target properties in Cu-Co-Si alloys via machine learning as well as two independent studies on the physical origin of this interrelation that has been further strengthened during the last few years.

Изменение Параметров Образования Вакансий И Самодиффузии В Различных Полиморфных Модификациях Железа

“…Из формулы (11) легко найти выражения для первого (γ o ) и второго (q o ) параметров Грюнайзена для безвакансионного кристалла, которые имеют вид…”

“…Поскольку, согласно (11), температура Дэбая не зависит от температуры при изохорическом нагреве кристалла, изохорную теплоемкость и изобарный коэффициент теплового объемного расширения для безвакансионного кристалла можно определить в виде [15]:…”

“…Активационные параметры (т. е. параметры образования электронейтральных вакансий и самодифузии атомов) в различных полиморфных модификациях железа изучают давно, но на сегодняшний день надежные экспериментальные данные получены только для энтальпии (h i ) и объема (v i ) активационного процесса [3][4][5][6][7][8][9][10][11]. Методов измерения либо расчета энтропии (s i ) и связанной с ней энергии Гиббса (g i = h i −T s i ) активационного процесса пока нет [7][8][9][10][11]. Здесь индекс i = v или d для образования электронейтральных вакансий или для самодиффузии атомов соответственно.…”

Changing the parameters of vacancy formation and self-diffusion in various polymorphic modifications of iron

“…Activation parameters (i.e., the parameters of formation of electrically neutral vacancies and self-diffusion of atoms) in various polymorphic modifications of iron were studied for a long time, but to date, reliable experimental data were obtained only for enthalpy (h i ) and volume (v i ) of activation process [3][4][5][6][7][8][9][10][11]. Yet, there are no methods for measuring or calculating the entropy (s i ) and associated Gibbs energy (g i = h i −T s i ) of the activation process [7][8][9][10][11]. Here the index is i = v or d for the formation of electrically neutral vacancies or for the self-diffusion of atoms, respectively.…”

Microstructural engineering through high enthalpy states: implications for far-from-equilibrium processing of structural alloys

“…The refinement of grains through severe plastic deformation is a top-down approach (McFadden et al, 1999;Mishra et al, 1999;Setman et al, 2010). When the lattice defect densities of 0-dimension (vacancies) (Damask and Dienes, 1971;Mishin et al, 2009;Kobelev and Khonik, 2018;Korte-Kerzel et al, 2021;Varotsos et al, 2022), 1-dimension (dislocations) (Gibbs, 1969)and 2-dimensions (interfaces) are incorporated in a singlephase alloy, the energy state is enhanced. This is schematically illustrated in Figure 1A.…”