Open Science Research Excellence
%0 Journal Article
%A Vera Varazashvili and  Murman Tsarakhov and  Tamar Mirianashvili and  Teimuraz Pavlenishvili and  Tengiz Machaladze and  Mzia Khundadze
%D 2015 
%J  International Journal of Chemical, Molecular, Nuclear, Materials and Metallurgical Engineering
%B World Academy of Science, Engineering and Technology
%I International Science Index 105, 2015
%T Thermodynamic Approach of Lanthanide-Iron Double Oxides Formation
%V 105
%X Standard Gibbs energy of formation ΔGfor(298.15) of
lanthanide-iron double oxides of garnet-type crystal structure
R3Fe5O12 - RIG (R – are rare earth ions) from initial oxides are
evaluated. The calculation is based on the data of standard entropies
S298.15 and standard enthalpies ΔH298.15 of formation of compounds
which are involved in the process of garnets synthesis. Gibbs energy
of formation is presented as temperature function ΔGfor(T) for the
range 300-1600K. The necessary starting thermodynamic data were
obtained from calorimetric study of heat capacity – temperature
functions and by using the semi-empirical method for calculation of
ΔH298.15 of formation. Thermodynamic functions for standard
temperature – enthalpy, entropy and Gibbs energy - are
recommended as reference data for technological evaluations.
Through the structural series of rare earth-iron garnets the correlation
between thermodynamic properties and characteristics of lanthanide
ions are elucidated.
%P 1109 - 1112