Low temperature 151Eu and 57Fe Mössbauer study of mechanically alloyed EuFeO3

Abstract

Low temperature 57 Fe Mössbauer spectra of mechanically alloyed EuFeO 3 prepared by mechanical alloying depicts an interesting transformation in its hyperfine magnetic state, from a triple phase magnetic system at room temperature to a single phase ferromagnetic state at 20 K. The hyperfine magnetic field increased by 12% at 20 K from its room temperature. The isomer shift and quadrupole splitting values exhibit a peak around 200 K. Low temperature 151 Eu Mössbauer measurements show that the line-width increased to its maximum value at 80 K which is 45% compared to its room temperature value not enough to suggest splitting.Keywords Mössbauer · Orthoferrites · Mechanical alloying IntroductionRare-earth ferrite perovskite type oxides, RTO 3 R = rare-earth and T = transition metal, are important for many technological applications [1][2][3][4][5][6][7]. Perovskite oxides, EuFe x Mn 1−x O 3 , exhibit many specific properties and structural transformations such as Jahn Teller distortion [8]. To date orthoferrite RFeO 3 are the only iron system in which high pressure induced spin cross over is directly observed [9]. Orthoferrites such as EuFeO 3 make it possible to see fine features of electronic structure versus rare-earth atomic number and almost negligible changes of local structure [10]. Mössbauer spectroscopy is best suited to study ferrite oxides and in particular EuFeO 3 since this is one of the rare cases where both the rare-earth and transition metal sites can be probed. To our knowledge there are only two such studies so far and both were carried out at room temperature only [11,12]. This work is the first to