Thermodynamic Properties of Fe 3 O 4 ‐FeV 2 O 4 and Fe 3 O 4 ‐FeCr 2 O 4 Spinel Solid Solutions
Abstract
Solid solutions of Fe304‐FeV204 and Fe304‐FeCr204 were prepared and equilibrated with Pt under controlled streams of CO/CO, gas mixtures at 1673 K. The concentration of Fe in Pt was used to determine the activity of Fe304 in the solid solutions. The activity of the second component was calculated by Gibbshhem integration. From these data, the Gibbs energy of mixing was derived for both systems. The experimental results and theoretical values which are determined from calculated cation distribution compare favorably in the case of vanadite solid solutions but not in the case of chromite solid solutions. The difference is attributed to a heat term arising from lattice distortion due to cation size difference. The positive heat of mixing will give rise to a miscibility gap in the system Fe304‐FeCr204 at lower temperatures.
Metrics
Citation History
Topics
Related Documents
Ferrielectricity in Rb2ZnCl4, Rb2ZnBr4, {N(CH3)4}2ZnCl4, {N(CH3)4}2CoCl4 and K2ZnCl4
Shozo SawadaToshihisa YamaguchiNaomi Shibayama
Mehrkernige Oxo-Vanadium- und Oxo-Molybdän-Komplexe mit dem Dianion der Quadratsäure als Brückenligand. Strukturen von [C(NH2)3]4[V2O2F4(C4O4)2]·4H2O, [nBu4N]4[V3O3F4(C4O4)3]·2H2O, [Et4N]3[Mo3O8F(C4O4)2], [Et4N]4[Mo4O10F6(C4O4)] und [ Et4N]3[Mo2O3Cl3(C4O4)2] / Polynuclear Complexes of Oxo-Vanadium and Oxo-Molybdenum with the Dianion of Squaric Acid as Bridging Ligand. Crystal Structures of [C(NH2)3]4[V2O2F4(C4O4)2]·4H2O, [nBu4N]4[V3O3F4(C4O4)3]·2H2O, [Et4N]3[Mo3O8F(C4O4)2], [Et4N]4[Mo4O10F6(C4O4)] and [ Et4N]3[Mo2O3Cl3(C4O4)2]
Martin P. HilbersMargita MeiwaldRainer Mattes
Variationen modulo 4–4+, 4+3–3+4–, 4–5+, 5–4+4–5+4–4+ bei Seltenerdcarbidhalogeniden
Hansjürgen MattauschArndt Simon
Thermodynamic Properties of Fe 3 O 4 ‐FeAl 2 O4 Spinel Solid Solutions
Anthony PetricΚ. T. JacobC. B. Alcock
The Mixed Polychalcogenorhenate(IV) Anions [Re4Q4(S3)4(S4)2]4- (Q = Se, Te): Syntheses and Crystal Structures of [NMe4]5[Me2NH2]3[Re4Se4(S3)4(S4)2]2·2.25H2O and [NH4]4[Re4Te4(S3)4(S4)2]·8H2O
Yuri V. MironovMichael A. PellThomas E. Albrecht‐SchmittJames A. Ibers