Features of phase formation and state of iron in the quasibinary system FeTe1.65-TiTe1.65.

A series of tellurides Fe_xTi_{1− x} Te_1.65 ( x = 0, 0.1, 0.2 ..., 1.0) synthesized at 850°C were studied by X-ray phase and X-ray fluorescent analysis and Møssbauer spectroscopy on ⁵⁷Fe. In this series two solid solutions are formed: phases I and II with homogeneity regions within the limits of 0 ≤ x ≤ 0.3 and 0.9 ≤ x ≤ 1.0, respectively. Iron in this series exists in two various states: Fe²⁺ _sym and Fe²⁺ _asym as differentiated from the series of tellurides Fe_xTi_{1− x} Te_1.45 where three states of iron Fe²⁺ _sym, Fe²⁺ _asym, and Fe⁰ were found. On passing from Fe_xTi_{1− x} Te_1.45 to Fe_xTi_{1− x} Te_1.65 the number of formed phases decreases, and phase relations become simpler. The absence of Fe⁰ from phase I of tellurides Fe_xTi_{1− x} Te_1.65 can point to the fact that TiTe_1.45 and TiTe_1.65 belong to different homogeneity regions. [ABSTRACT FROM AUTHOR]