Том 475, № 2 (2017)

Erbium titanate with a pyrochlore structure has been synthesized by a ceramic method from stoichiometric Er₂O₃–TiO₂ mixtures at 1673–1773 K. The high-temperature heat capacity of Er₂Ti₂O₇ (320–1000 K) has been studied by differential scanning calorimetry. The thermodynamic functions of this oxide compound—enthalpy and entropy changes and reduced Gibbs—have been calculated from the experimental dependence C_P = f(T).

A fundamentally new solution of the challenge of producing alloys in the Fe–Co system with an oxygen concentration below 10 ppm (10^–3%) has been for the first time justified and demonstrated. A thermodynamic analysis showed that decreasing the pressure of the gas phase over the melt significantly increases the deoxidizing power of carbon. At cobalt and carbon contents characteristic of soft- and hard-magnetic alloys and a total pressure of 0.01 atm, the oxygen concentration was 10–1 ppm (10^–3–10^–4%). With increasing cobalt content of the melt, the deoxidizing power of carbon increases. The curves of the oxygen solubility in carbon-containing iron–cobalt melts pass through a minimum, which shifts toward lower carbon contents with increasing cobalt content of the melt.