(Mg,Ni)Ga2O4 Solid Solution with a Spinel Structure

Doklady Chemistry - The boundaries of Mg1 – xNixGa2O4 solid solutions (0 ≤ х ≤ 0.5) with a spinel structure synthesized by the gel combustion method,...     

The standard enthalpies of formation of mixed antimony and bismuth oxides

The Bi₂O₃-BiSbO₄ and BiSbO₄-Sb₂O₄ sections of the phase diagram of the Bi-Sb-O system were studied by the Knudsen effusion method with mass spectrometric analysis of the gas phase. The standard enthalpies of formation of the Bi₃SbO₆(g), Bi₂Sb₂O₆(g), BiSb₃O₆(g), Bi₃SbO₇(s), and BiSbO₄(s) mixed antimony-bismuth oxides and the standard enthalpies of some reactions with the participation of these oxides were calculated.     

Specifics of phase transformations in Li/W/Mn/SiO2 composites at influence of methane-oxygen and hydrogen-air mixtures

Li/W/Mn/SiO₂ composites were studied immediately after sol-gel or solid-phase synthesis and the high-temperature exposure to methane-oxygen and hydrogen-air mixtures. The phase compositions of these catalysts, which determines their catalytic activities in the oxidative coupling of methane, were shown to depend on the method of synthesis, the ratio of cations, and the composition of the submitted gas mixture.     

Low-temperature heat capacity and thermal behavior of Zn<Subscript>0.98</Subscript>Co<Subscript>0.02</Subscript>O in the high-temperature region

The low-temperature heat capacity of Zn _0.98Co_0.02O oxide was measured by adiabatic calorimetry. The formation of a solid solution was shown to be accompanied by a change in the entropy by 0.4 J/(K mol). No anomalies in the heat capacity or the thermal behavior confirming the phase transformations found earlier by other methods were observed. A heat capacity anomaly was revealed below 15 K and tentatively attributed to a change in the magnetic properties of the substance.     

Solid-phase synthesis of intermetallic compounds Al<Subscript>13</Subscript>Co<Subscript>4</Subscript>, Al<Subscript>13</Subscript>Fe<Subscript>4</Subscript>, and Al<Subscript>13</Subscript>Co<Subscript>2</Subscript>Fe<Subscript>2</Subscript>

Intermetallic compounds Al₁₃Co₄, Al₁₃Fe₄, and Al₁₃Co₂Fe₂ were obtained by solid-phase synthesis in air at temperatures below 600°C using precursor metals subjected to mechanochemical preactivation. The phase composition of the synthesized aluminides and composites Al₁₃Co₄/SiO₂ and Al₁₃Fe₄/SiO₂ was analyzed.     

DSC study of YaBabCucO72212;δ homogeneity in the region 1050–1300 K

Phase transitions of the compositions Y_1±xBa_2±yCu_3±zO_72212; (x,y=0–0.2;z=0–0.5; step 0.1) were studied by DSC in argon atmosphere in the temperature range 1050–1300 K. The formation of three polymorphous modifications of the 123 phase was observed. The solubilities of yttrium, barium and copper oxides in every modification were determined. TheT-x-y phase microdiagram for the 123 phase was mapped out.