Formation of oxide phases in the system Eu2O3-Fe2O3

Evolution of oxide phases in the Eu2O3-Fe2O3 system was investigated by X-r ay powder diffraction, Fe-57 and Eu-151 Mossbauer spectroscopy and Fourier transform infrared spectroscopy. Samples were prepared by the solid state r eaction of the corresponding oxides for two molar ratios, Eu2O3 : Fe2O3 = 1 : 1 and 3 : 5. After heating the mixed oxide powder with molar ratio Eu2O3 : Fe2O3 =1:1 up to 900 degrees C, EuFeO3 and traces of Eu2O3 were detected by XRD, while after additional heating up to 1100 degrees C traces of Eu3F e5O12 (EuIG) were also detected. Fe-57 and Eu-151 Mossbauer spectroscopy sh owed the presence of EuFeO3. For the molar ratio Eu2O3 : Fe2O3 = 3 : 5, EuI G was formed between 1100 and 1300 degrees C. In the sample produced at 130 0 degrees C, the measured hyperfine fields at the iron sites, at room tempe rature, were H-a= 495 and H-d = 402 kOe, and the hyperfine fields at the eu ropium sites, at 90 K, were H-I = 631 kOe and H-II = 572 kOe. Europium orth oferrite was the intermediate phase in the garnet formation. Assignations o f IR bands corresponding to EuFeO3 and EuIG are discussed. Mechanical activ ation of the mixed oxide powder was important for the formation of polycrys talline EuIG, as a single phase.