High current density measurements of giant magnetoresistive spin-valves for magnetic recording and sensor applications

High current density measurements on giant magnetoresistive NiFe-Cu-NiFe-FeMn spin-valve devices are presented. The spin-valve magnetoresistive response, Delta R/R, is highly temperature dependent; at temperatures near the blocking temperature there is a considerable reduction of pinning field and decrease in device response. It is desirable to measure certain high current density effects such as electromigration and self-field effects separately from the effects of ohmic heating. For this purpose, we introduce pulsed current techniques necessary to reduce ohmic heating in wafer-level device measurements and we deduce a required pulse width of 15 ns to minimize device heating.