Several studies of internal fiiction have been performed on silicate glasses. This work has the specificity to refer to isothermal mechanical spectroscopy over a large frequency range and for temperatures between 290 K and 520 K. Experiments were carried out with a single alkali silicate glass and two mixed alkali silicate glasses in order to observe the mixed alkali effect, to follow its evolu...

The stability of two-component clusters consisting of light (Na or K) and heavy (Rb or Cs) alkali atoms formed on helium nanodroplets is studied by femtosecond laser ionization in combination with mass spectrometry. Characteristic stability patterns reflecting electron shell-closures are observed in dependence of the total number of atoms contained in the mixed clusters. Faster decay of the sta...

In this work, mixed alkali metaphosphate glasses based on K-Na, Rb-Na, Rb-Li, Cs-Na and Cs-Li combinations were studied by differential scanning calorimetry (DSC), complex impedance spectroscopy, and Raman spectroscopy. DSC analyses show that both the glass transition (Tg) and melting temperatures (Tm) exhibit a clear mixed-ion effect. The ionic conductivity shows a strong mixed-ion effect and ...

References ‘C. T. Moynihan, N. S . Saad, D. C. Tran, and A. V. Lesikar, “Mixed-Alkali Effect in the Dilute Foreign-Alkali Region, Failure of the StrongElectrolyte/Cationic Interaction Model,” J . Am. Ceram. Soc., 63 [7-81 458-64 (1980). 2 J . W. Fleming, Jr., and D. E. Day, “Relation of Alkali Mobility and Mechanical Relaxation in Mixed Alkali Glasses,” ibid. , 55 [4] 18692 (1972). 3G. Tomandl ...

The “mixed alkali effect” is one of the classical anomalies of glass science. We report here an interesting phenomenon “Mixed Alkali Effect” observed for a series of Cu ions doped xLi2O-(30x)Na2O-70B2O3 (5 ≤ x ≤ 25) glasses, investigated by EPR and optical absorption techniques. The EPR spectra of all the investigated samples exhibit resonance signals characteristic of Cu ions in octahedral sit...