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Abstract : |
A homogeneous SiO2-Na2O-Fe2O3 glass containing 4.6% Fe2O3 was prepared and devitrified to produce a glass ceramic containing the magnetic compound Na5Fe(SiO3)(4). The DC magnetic susceptibility measurements performed on both samples have shown that the magnetic ion-ion interaction is antiferromagnetic and is stronger in the crystallized sample. It was also shown that M versus H data at different temperatures do not collapse to a single curve in the M versus HIT representation, for either the glass or the heat treated sample. But the spread of the data is larger in the heat treated sample, further indicating a stronger interaction in the crystalline sample. The M versus H curves for the glass sample were fitted with Brillouin function by keeping the total number of magnetic ions constant and varying the proportion of ferrous ions until a best fit was achieved. The [Fe2+]/[Fe-total] ratio obtained from the fit is in good agreement with the value obtained from X-ray photoelectron spectroscopy (XPS) performed on the glass sample. (C) 1998 Elsevier Science B.V. All rights reserved., |
