The current-voltage (I-V) characteristics associated with self-heating
hotspots In HTS thin films patterned into several different geometrie
s have been investigated under both current-biased and voltage-biased
conditions. The hysteretic behavior of the I-V characteristics as a fu
nction of sample temperature are in agreement with behavior predicted
by resistive hotspot models for superconducting bridges, Additionally,
the effect of magnetic fields on tbe current required to generate, as
well as maintain, II normal hotspot has been investigated. Finally, t
he characteristics of voltage pulses resulting from a step increase in
current have been examined to study the propagation of hot spots in H
TS films.