High‐performance varistors prepared by hot‐dipping tin oxide thin films in Sb 2 O 3 powder: Influence of temperature

A series of SnO x –Sb 2 O 3 thin film varistors were fabricated through hot‐dipping tin oxide films deposited by radio‐frequency magnetron sputtering in Sb 2 O 3 powder at varied temperatures in air. With the increase in hot‐dipping temperature ( HDT ) from 200°C to 600°C, the nonlinear coefficient (α) of the samples increased first and then decreased, reaching the maximum at 500°C, which was mainly determined by the completeness of high‐resistant Sb 2 O 3 layer at tin oxide grain boundary and the chemical composition of tin oxide films. Correspondingly, the leakage current ( I L ) decreased first and increased later. The breakdown electric field ( E 100 mA ) decreased constantly with increasing HDT . The SnO x –Sb 2 O 3 film varistors prepared at 500°C exhibited the optimum nonlinear properties with the maximum α of 10.88, the minimum I L of 36.3 mA/cm 2 , and an E 100mA of 0.0188 V/nm. The obtained nanoscaled film varistors would be promising in electrical/electronic devices working in low voltage.