Copper ion beam emission in solid electrolyte Rb₄Cu₁₆I_6.5Cl_13.5

Copper ion conducting solid electrolyte Rb_4Cu_16I_6.5Cl_13.5 was prepared by means of mechano-chemical method. The structure and morphology of the powder was investigated by x-ray diffraction and scanning electron microscopy. The grain size was estimated to be 0.2-0.9 μm and the ionic conductivity at room temperature was approximately 0.206 S/cm. The solid electrolyte Rb_4Cu_16I_6.5Cl_13.5 was exploited for copper ion beam generation. The copper ion emission current of several nA was successfully obtained at acceleration voltages of 15 kV and temperature of 197 ^\circC in vacuum of 2.1\times10^-4 Pa. A good linear correlation between the logarithmic ion current (\log I) and the square root of the acceleration voltage (U_\rm acc) at high voltage range was obtained, suggesting the Schottky emission mechanism in the process of copper ion beam generation.