Naslov
Formation of oxide phases in the system Eu2O3-Fe2O3

Autori
Ristić, Mira ; Nowik, Israel ; Popović, Stanko ; Musić, Svetozar

Izvornik
Croatica Chemica Acta (0011-1643) 73 (2000), 2; 525-540

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
X-ray powder diffraction. Fe-57 and Eu-151 Mossbauer spectroscopy. FT-IR spectroscopy. Europium iron garnet. Europium orthoferrite

Sažetak
Evolution of oxide phases in the Eu2O3-Fe2O3 system was investigated by X-ray powder diffraction, Fe-57 and Eu-151 Mossbauer spectroscopy and Fourier transform infrared spectroscopy. Samples were prepared by the solid state reaction 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 Eu3Fe5O12 (EuIG) were also detected. Fe-57 and Eu-151 Mossbauer spectroscopy showed the presence of EuFeO3. For the molar ratio Eu2O3 : Fe2O3 = 3 : 5, EuIG was formed between 1100 and 1300 degrees C. In the sample produced at 1300 degrees C, the measured hyperfine fields at the iron sites, at room temperature, were H-a= 495 and H-d = 402 kOe, and the hyperfine fields at the europium sites, at 90 K, were H-I = 631 kOe and H-II = 572 kOe. Europium orthoferrite was the intermediate phase in the garnet formation. Assignations of IR bands corresponding to EuFeO3 and EuIG are discussed. Mechanical activation of the mixed oxide powder was important for the formation of polycrystalline EuIG, as a single phase.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

POVEZANOST RADA