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End date: 1999Subject: search.filters.subject.Measure theory

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    A Mössbauer effect study of barium ferrite ball-milled in air
    (Hyperfine Interactions, 1994) Jayasuriya, K.D.; Kaczmarek, W.A.; Wu, E.; Campbell, S.J.
    The effects of dry-milling BaFe12O19 in air for periods of 190, 360, 590, 690 and 1000 h have been investigated by X-ray diffraction and M�ssbauer effect measurements. The sizes of the BaFe12O19 particles decrease on milling, as expected, although a partial decomposition of BaFe12O19 to ?-Fe2O3 is found to take place on extended milling (1000 h). The room temperature M�ssbauer spectra are consistent with superparamagnetic relaxation associated with the fine BaFe12O19 and ?-Fe2O3 particles. The X-ray diffraction patterns of all the milled samples exhibit features indicative of a disordered structural state, consistent with the nanoscale particles and a nanostructured state.
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    A Mössbauer study of ball-milled Co?Fe?Si?B: II: with surfactants
    (Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1993) Jayasuriya, K.D.; Campbell, S.J.; Calka, A.; Jing, J.
    The use of a range of organic surface active substances in the ball milling of Co?Fe?Si?B has been studied by X-ray diffraction and M�ssbauer effect measurements. Effects characteristic of superparamagnetic relaxation of the magnetic moments are observed in the M�ssbauer spectra of samples milled with either an anionic or a cationic surfactant. This behaviour is linked with the decreased particle size and high shape homogeneity of surfactant-aided milled samples compared with the amorphous powders resulting from standard dry milling. Impurity iron-oxide phases are also found to occur in samples milled in the presence of surfactants.
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    A Mössbauer study of ball-milled Co?Fe?Si?B: I: dry milling
    (Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1993) Jayasuriya, K.D.; Campbell, S.J.; Calka, A.; Jing, J.
    X-ray diffraction and M�ssbauer effect measurements of ball-milled Co?Fe?Si?B material which had first been re-crystallized from amorphous melt-spun ribbon are presented. Fully amorphous powders have been obtained after only 50 h milling with a ball-to-powder ratio of BPR ? 84. The amorphous powders exhibit chemical and structural inhomogeneities compared with the starting melt-spun amorphous ribbons.