| NUKLEONIKA 2013, 58(1):47-51
HYPERFINE INTERACTIONS AND IRREVERSIBLE MAGNETIC BEHAVIOR IN MULTIFERROIC AURIVILLIUS COMPOUNDSEl¿bieta Jartych1, Karolina G¹ska2, Janusz PrzewoŸnik2, Czes³aw Kapusta2, Agata Lisiñska-Czekaj3, Dionizy Czekaj3, Zbigniew Surowiec4 1 Lublin University of Technology, Faculty of Electrical Engineering and Computer Science, Institute of Electronics and Information Technology, 38A Nadbystrzycka Str., 20-618 Lublin, Poland 2 AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Department of Solid State Physics, al. A. Mickiewicza 30, 30-059 Krakow, Poland 3 University of Silesia, Institute of Materials Science, 2 Œnie¿na Str., 41-200 Sosnowiec, Poland 4 Maria Curie-Sklodowska University, Institute of Physics, 1 M. Curie-Sklodowskiej Sq., 20-031 Lublin, Poland In this work investigations of structure and magnetic properties of conventionally sintered Bim+1Ti3Fem–3O3m+3 compounds with 4 =< m =< 8 were performed using X-ray diffraction, Mössbauer spectroscopy and vibrating sample magnetometry. Room-temperature Mössbauer spectra of the compounds correspond to a paramagnetic state, however, low temperature measurements (80 K) reveal the antiferromagnetic state with a residual paramagnetic phase. Temperature dependencies of magnetic susceptibility, provided magnetic ordering temperatures and revealed an irreversibility in Aurivillius compounds with m >= 5. In the case of Bi5Ti3FeO15 compound the chi sigma(T) dependence shows a paramagnetic behavior down to 2 K. The Bi6Ti3Fe2O18 compound reveals a magnetic ordering at 11 K. The compounds with m = 6–8 show a magnetic ordering at temperatures higher than 200 K. Highly irreversible character of their temperature dependencies of chi sigma indicates a spin-glass type disordered magnetism with frustration due to a random distribution of Fe on Ti at their sites. Close X |