INFLUENCE OF TI SN RATIO AND SYNTHESIS METHOD IN IRON NIOBATE DOPED WITH SN AND TI - [FE0.4TI0.2-XSNXNB0.4O2 SOLID-SOLUTIONS]/

In this study, Fe0.4Ti0.2-xSnxNb0.4O2 solid solutions have been synthe sized from both ceramic and gel colloidal methods from Fe2O3, Nb2O5, T iO2, SnCl2.2H(2)O and FeCl3, NbCl5, TiCl4, SnCl2.2H(2)O respectively. Two kinds of solid solutions with orthorhombic and tetragonal FeNbO4 s tructures have been obtained. The results indicate that solid solution s structure depends on firing temperature, composition, i. e. Ti/Sn ra tio and synthesis method. The optimal composition range to obtain soli d solutions with low temperature structures (monoclinic and orthorhomb ic) is 0.10 less than or equal to x less than or equal to 0.15, but on ly in samples prepared by colloidal gel method, a single phase with th ese structures is obtained (900-1100 degrees C). Solid solutions with tetragonal structure are stable at high temperature and a single phase with this structure is obtained at 1300 degrees C in samples with x < 0.10.