Ag+ ion emission from a sharp Ag2O-Al2O3-P2O5-SiO2 glass-fiber emitter

Ag+ ion conducting xAg2O·(30 − x)Al2O3·55P2O5·15SiO2 (x = 20 and 25, mol%) glasses were prepared using a conventional melting method, and structures and glass transition temperature were investigated using X-ray diffraction (XRD), differential scanning calorimetry (DSC), ultraviolet-visible (UV-Vis) and Fourier transform infrared (FTIR) spectroscopies. Impedance measurement reveals the glass with x = 25 shows a high Ag+ ion conductivity of 3 × 10−3 S cm−1 at 300 °C. Ag+ ion emission measurement was carried out using a sharpened glass fiber tip less than 1 μm, and the emission current was successfully observed above the acceleration voltage of 4 kV at 300 °C and 4 × 10−5 Pa. Silver particles were confirmed on the target substrate after the Ag+ emission measurement. A good linear correlation is obtained between log(current) and square root of the voltage, suggesting the emission of Ag+ ion from the tip of glass fiber is expressed by Schottky model. In this ion emission method, a plasma is not required for ionization and the ion emission mechanism is simple, and various ion conducting glasses can be applied for the emitter of ion gun.