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Abstract : |
Sodium copper silicate glasses of composition (SiO2)(0.70-x) (Na2O)(0.30)(CuO)(x) where 0 less than or equal to x less than or equal to 0.20 were studied by magnetisation and x-ray photoelectron spectroscopy (XPS) techniques. The M versus H data at different temperatures collapses to a single curve in the M versus H/T representation for all the glass compositions studied, indicating that the magnetic ion-ion interaction is weak and that Cu2+ behaves paramagnetically in these glasses. The M versus H curves have been fitted with a Brillouin function by maintaining the number of magnetic ions as the fitting parameter and deducing the number of Cu2+ ions in each glass sample from the best fit to the experimental data. XPS has also been used to determine the number of Cu2+ ions in the glass samples by deconvoluting the Cu2p(3/2) photoelectron spectra into contributions from Cu2+ ions detected by XPS is much lower than that obtained from bulk magnetic measurements. A possible origin of this difference is indicated., |