Giant dielectric permittivity in aligned silver nanowires grown within (AgI)(AgPO₃) glasses

Abstract

Silver nanowires of diameters in the range 0.5-3.5 nm have been grown within (AgI)(AgPO₃) glasses by subjecting them to an electrodeposition process. Silver nanowires are found to be aligned in the glass containing a high concentration of Ag ions. The electrical resistivity of the composites containing silver nanowires exhibits metallic behavior. The electrical conductivity of the precursor glass shows a frequency variation with an exponent n ~ 2/3. This indicates a three-dimensional motion of silver ions in the glass when an electric field is applied. The aligned nanowire formation is believed to arise due to an increase in the internal electrical field as a consequence of the aligned dipoles formed by Ag and I ions within the glass matrix. Some of the wires are broken and they give rise to a giant dielectric permittivity (as extracted from the high-frequency value) due to Gorkov-Eliashberg and Rice-Bernasconi mechanisms.