Appearance mechanism of oscillatory current related to hot spot

Abstract

A hot spot appeared in SmBa₂Cu₃O_7-δ ceramic rod when a voltage above a threshold was applied. Under low oxygen partial pressure, a damped sinusoidal oscillatory current was generated in the rod after the appearance of the hot spot. In this research, the appearance of the oscillatory current was investigated by measuring the current as a function of time, resistivity temperature characteristics and temperature distribution of the rod. As a result of investigations, the appearance of the oscillatory current was considered to be caused by changing temperature of PTC and NTC regions in the rod.