ULTRASONIC VELOCITY AND DENSITY-MEASUREMENTS OF MOLTEN CUCL-CUBR MIXTURES

The ultrasonic velocity, sound attenuation and density measurements have been carried out for molten Cu(Cl1-xBrx) mixtures at temperatures from the melting points to about 800-degrees-C to investigate the thermodynamic and dynamical properties. The adiabatic compressibility of this system has obtained from the observed ultrasonic velocity and density. The observed compressibility has an interesting concentration dependence of positive deviation from linear one and has the maximum around Cu(Cl0.2Br0.8) which suggests large fluctuations in the molten mixtures compared with pure molten CuCl and CuBr. The sound attenuation shows large temperature dependence around x=0.2 and 0.8. We discuss the thermodynamic and dynamical properties of the molten mixtures from a view point of chemical bond, taking the difference of ionicity between Cl and Br into account.