Solid‐state equilibrium relations in the Ternary Systems TeO2MoO3MoO2 and TeO2MoO3Te

Abstract

AbstractIn a study of the solid‐state reactions in the ternary systems TeO2MoO3MoO2 and TeO2MoO3Te, approximately 70 selected compositions were sintered at 550°C to attain equilibrium conditions, and solid‐state equilibrium relations were characterized by x‐ray diffraction. In a large composition range, the interaction of TeO2 and MoO3 with the reducing agents MoO2 or Te leads to the reduced ternary oxide TeMo4O13 (m. p. 748°C), in addition to Te2MoO7, Te and (intermediate) molybdenum oxides. The compatibility relations for the binary systems TeO2MoO2 and MoO3Te are presented for the first time. In the TeO2MoO2 system, three‐phase regions are found: (Te2MoO7TeO2Te) on the TeO2and (TeMo4O13MoO2Te) on the MoO2‐rich sides with (TeMo4O13Te2MoO7Te) in the intermediate region. In the MoO3Te system, three‐phase regions (TeMo4O13MoO2Te), (TeMo4O13Mo4O11MoO2) and (TeMo4O13MoO3Mo4O11) were detected.TeMo4O13 presents two allotropic forms (α′ for T < 450°C, α for T > 450°C). Both structures have been characterized by I.R. and optical reflectance spectroscopy. Unit cell dimensions are also given.