Magnetic properties of the ternary oxide glasses, Li2O-B2 O3-Fe2O3 from 57Fe Mössbauer spectroscopy

57Fe Mössbauer spectroscopy has been combined with bulk magnetic measurements to determine the valence state and coordination of iron as well as the magnetic properties of the ternary oxide glasses, Li2O-B 2O3-Fe 2O3. In all investigated glasses (≤ 8.4 at % Fe), the Fe3+ ions coexist in tetrahedral and octahedral coordinations ; the presence of Fe2+ ions ( < 15 %), which is observed in some glasses, is related to preparation conditions. The magnetic properties of the glasses are governed by the iron content. At low iron concentration (< 3 at %), isolated Fe3+ ions coexist with antiferromagnetic dimers and trimers. At large iron content (3.8 to 8.4 at %) the glasses undergo a mictomagnetic transition to a speromagnetic ordered state. The freezing temperature (Tf), which is frequency dependent, is found to follow a Fulcher law in one sample (5.8 at % Fe) investigated in detail

Propriétés magnétiques d'un oxyde amorphe riche en fer : Fe2 O3 (30) BaO (45) B2O3 (25)

La transition magnétique d'un oxyde amorphe riche en fer a été caractérisée par des mesures d'aimantation et susceptibilité magnétique et par spectroscopie Môssbauer de 57Fe. On note de fortes interactions antiferromagnétiques dans le verre et un comportement mictomagnétique à basse température. L'ordre magnétique au-dessous de la transition est de nature spéromagnétique

57Fe ABSORPTION AND EMISSION SPECTROSCOPY IN SOME COBALT ACETYLACETONATE COMPLEXES [Co (acac)3, Co (acac)2, Co (acac)2·2H2O]

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INTERACTIONS AND PRECIPITATIONS IN DILUTE TERNARY Fe Sb M ALLOYS (M = Ti, V, Cr, Mn, Co, AND Ni)

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Electronic and magnetic properties of some rare-earth dihydrides and dideuterides

Mössbauer spectroscopy has been used to study the electronic and magnetic properties of a number of rare-earth dihydrides and dideuterides. In stoichiometric ErH2 and DyH2, magnetic transitions and crystal field ground states have been established. In non-stoichiometric compounds DyH2+x and (Er)HoH2+x changes of the rare-earth point symmetry due to distributions in hydrogen site occupations are seen. This results in increases in the magnetic transition temperatures and distributions in the magnetic moments

57Fe HYPERFINE INTERACTION MEASUREMENTS IN AN IRON CONCENTRATED OXIDE GLASS Fe203(30)BaO(45)B2O3(25)

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