Low temperature route to the multiferroic FeAlO3: XRD and Mössbauer characterizations

Abstract

A low temperature route to the multiferroic FeAlO 3 is being reported. Four different synthesis routes namely, the solid-state route, the co-precipitation route, the sol-gel route and the high-energy ball-milling route have been carried out. The as-prepared samples of all the four routes have been subjected to sintering at 1,000 • C. The sintered samples were characterized by X-ray diffraction, thermogravimetric analysis and Mössbauer spectroscopy. X-ray diffractograms revealed the coexistence of the orthorhombic multiferroic phase along with some unreacted impurities. Mössbauer spectroscopy confirmed the presence of the desired multiferroic phase along with residual hematite. A discussion on the various aspects of the different synthesis procedures is presented.

An experimental approach for synthesis of Fe-Al-O multiferroic fibrous material

“…Only these phases are identified among the huge number of Fe-Al-O compounds known from the powder diffraction [8]. Besides, no traces from the very stable hematite α-Fe 2 O 3 or alumina α-Al 2 O 3 are dissolved in these XRD spectra which usually accompany the synthesis of FeAlO 3 with other methods as for instance the solid state reactions [5]. The results from XRD show that in both cases the fibrous material spun at optimal electrospinning conditions and thereafter calcinated during the two step thermal procedure is the multi-ferroic with practically same composition, e.g.…”

“…Regardless of this R&D importance only a few activities on the synthesis of single-phase FeAlO 3 have been reported. This is due to the very narrow range of stability of the multi-ferroic phase in the binary equilibrium diagram of Fe 2 O 3 -Al 2 O 3 [5] and of the extremely high stabilities of both hematite -a-Fe 2 O 3 and alumina -a-Al 2 O 3 , which hinders the reaction. Different experimental approaches are well known for synthesis of single-phase multi-ferroic FeAlO 3 [5], namely: solid-state, sol-gel, co-precipitation and the high-energy ball-milling methods.…”

The Effect of Synthetic Method and Annealing Temperature on Metal Site Preference in Al1–xGaxFeO3

“…It should be noted that higher annealing temperatures were required to form phase pure materials for Al rich compositions. 27,28 All samples studied were determined to be phase pure by powder Xray diffraction using a PANalytical Empyrean diffractometer and either Cu or Co Ka 1,2 radiation. Lattice constants for Al 1−x Ga x FeO 3 were determined using the X'Pert HighScore Plus software from PANalytical and an orthorhombic model of the crystal structure (Pna2 1 ).…”

Pack-Aliting in Thermitic Powder Mixture Obtained by Mechanical Alloying

“…The phase composition analysis of the mechanically alloyed mix powder ( fig. 3) shows the presence of all iron oxides FeO, Fe 3 O 4 , Fe 2 O 3 , Al and AlFeO 3 (double iron oxide and aluminum type Al 2 O 3 •Fe 2 O 3 ) compound with a perovskite, multiferroic structure [9].…”