Magnesium thermodynamic properties

The thermodynamic properties of magnesium make it a natural choice for use as an anode material in rechargeable batteries, as it may provide a considerably higher energy density than the commonly used lead-acid and nickel-cadmium systems, while in contrast to Pb and Cd, magnesium is inexpensive, environmentally friendly, and safe to handle. However, the development of Mg-ion batteries has so far been limited by the kinetics of Mg " " diffusion and the lack of suitable electrolytes. Actually, in spite of an expected general similarity between the processes of Li and Mg ion insertion into inorganic host materials, most of the compounds that exhibit fast and reversible Li ion insertion perform very poorly in Mg " ions. Hence, there... 

Sverjensky DA, Shock EL, Helgeson HC (1997) Prediction of flie thermodynamic properties of aqueous metal complexes to 1000°C and 5 kb. Geochim Cosmochim Acta 61 1359-1412 Tarutani T, Clayton RN, Mayeda TK (1969) The effect of polymorphism and magnesium substitution on oxygen isotope fractionation between calcium carbonate and water. Geochim Cosmochim Acta 33 987-996... 

The second form of precipitation cannot be understood from the thermodynamic properties of the solution the solution is undersaturated, even so, precipitation takes place on the surface. This process is called surface precipitation. In this case there are three possibilities. One of them is when the precipitate is formed in a monomolecular layer. The second possibility is coprecipitation, when a component in low concentration coprecipitates with another component in high concentration if it can be built into the crystal lattice (Section 1.2.4). In this case, the thickness can be higher than that in the monolayer. For example, cesium ions in very low concentration coprecipitate with iron and magnesium containing carbonates (Konya et al. 2005 Chapter 3, Section 3.1.2). These types of surface precipitation can quantitatively be described by the adsorption equations (Section 1.3.4.1). 

We have worked out a sufficiently precise and reliable system of consistent thermodynamic constants (Mel nik, 1972) especially for analysis of the conditions of formation of iron ores. In this work, in addition to the constants of crystalline minerals, data on the stability and thermodynamic properties of the original finely dispersed amorphous or cryptocrystalline iron, magnesium, and silica sediments were systematized for the first time. Such sediments are metastable solid phases which in nature are converted into stable crystalline minerals during diagenesis and low-rank metamor-... 

These five functions are used to calculate values of the various transformed thermodynamic properties at 298.15 K, pH 7, pMg 3, and ionic strength 0.25 M. Since the specified concentration of magnesium ions is so low, these values are not very different from the values calculated in the preceding chapter for the absence of magnesium ions. 

The standard formation properties of the species involved in atp + h2o = adp + pi are known at 298.15 K (1), and so it is possible to calculate A, G Ar, A, 5" ", A Ah, ATdAr W "/dpH, and dAr 5 "/dpH over a range of temperatures (2). This reaction is remarkable because the thermodynamic properties of the complex ions with magnesium are also known. This made it possible to calculate ten properties of this hydrolysis of atp as functions of temperature, pH, pMg, and ionic strength (3). Note that the number of Maxwell relations increases rapidly with the number of independent variables. 

Tsyplakova, M.M. and Strelets, Kh.L. (1969) Study of the thermodynamic properties of the magnesium-aluminum system. J. Appl. Chem. USSR, 42 (11), 2354-9. 

SAD/LIB] Sadowska, T., Libus, W., Thermodynamic properties and solution equilibria of aqueous bivalent transition metal nitrates and magnesium nitrate, J. Solution Chem., 11, (1982), 457-468. Cited on pages 203,204. 

Maclaurin series, A-65 to 67 Madelung constant, 12-32 Magnesium see also Elements electrical resistivity, 12-39 to 40 electron configuration, 1-18 to 19 heat capacity, 4-135 history, occurrence, uses, 4-1 to 42 ionization energy, 10-203 to 205 isotopes and their properties, 11-56 to 253 magnetic susceptibility, 4-142 to 147 molten, density, 4-139 to 141 thermal conductivity, 12-203 to 204 thermal properties, 12-201 to 202 thermodynamic properties, 5-1 to 3 vapor pressure, 6-61 to 90 vapor pressure, high temperature, 4-136 to 137... 

Cao] Cao, R., Li, G., Wu, X., Some Thermodynamic Properties in Process of Thermal Reduction of Magnesium with High Aluminium Alloy (in Chinese), Acta Metall. Sin., 21, A471-A476... 

Z. Dehouche, R. Djaozandry, 1. Huot, S. Body, 1. Goyette, T.K. Bose, R. Schulz, Influence of cycling on the thermodynamic and structure properties of nanocrystalhne magnesium based hydride, J. Alloys Compd. 305 (2000) 264-271. 

Application of SPD techniques to metal hydrides is a new field of research. Skripnyuk and Rabin were the first to use ECAP to improve the hydrogen storage properties of Mg-based alloys [254, 255]. The first study on ECAP-processed magnesium alloy ZK90 showed an improvement in sorption kinetics without loss of hydrogen capacity or change in thermodynamic parameters [254]. figure 4.12 shows comparable results for the Mg-Ni eutectic alloy [255]. 

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