Anomalous magnetization cycle ofUFe4Al8single crystals: A Mössbauer effect study

Abstract

An 57 Fe Mössbauer spectroscopy study was performed on an UFe 4 Al 8 single crystal, in an external magnetic field B ext , subtending an angle of 11°at the b axis. It shows that, even in low fields, the configuration of the Fe magnetic moments, Fe , is consistent with the canted antiferromagnetic order of Fe , established by single-crystal neutron diffraction in a field of 4.6 T. The canting of Fe is always observed towards the direction of the U magnetic moments U , clearly showing that it is induced by U rather than by B ext . At a certain value of B ext during the magnetic domain rotation, the direction of Fe is found to be temporarily frozen approximately along the direction of B ext . This confirms previous magnetization and magnetoresistance data, which show that for the same values of B ext , U is blocked perpendicularly to B ext . Furthermore, the present study reveals that this blocking is a metastable state with a relaxation time of a few hours, at 4.2 K.

Static and dynamic magnetic study of DyFexAl12−x (4≤x≤4.7)

“…1) consists of a symmetric doublet: line-widths and relative areas of each peak are equal within experimental error. The Mö ssbauer spectrum taken at 10 K shows a single sextet, as expected from a well-ordered compound with Fe atoms on only one crystallographic site [1,17,20]. These results are consistent with XRD data and clearly indicate that the Fe is only present on the 8f site.…”

“…In order to clarify the magnetism of the RFe x Al 12Àx compounds and within the frame of a systematic study of the A-Fe-Al (A ¼ U, Y) ternary systems undertaken by us in the last years [6,16,17], a detailed study by powder X-ray diffraction (XRD), magnetization, AC-susceptibility and 57 Fe Mö ssbauer spectroscopy of DyFe x Al 12Àx (4 x 4.7) was performed.…”

Crystal structure, 57Fe Mössbauer spectroscopy and magnetization of UxFe6Sn6 (0≤x≤0.6)

“…Among those with potentially useful applications as hard magnets, a large variety of magnetic interactions as well as unusual magnetic behaviours, such as in AFe 4 Al 8 [1][2][3][4][5][6][7], have been reported.…”

Characterization of the ternary uranium–iron aluminide UFe2Al10

“…This intermetallic compound displays quite unusual electrical transport and magnetic properties that were extensively studied [2][3][4][5][6].…”