Thermal characteristics of a PtMn GMR sensor subjected to square wave EOS pulses

Electrical overstress (EOS) pulses between 50 ns to 24 hours were applied to GMR stripes with a synthetic PtMn antiferromagnet (AFM) and a permalloy free layer. The temperature dependence of the sensors versus power and pulse width was measured and a simple phenomenological model was developed to analytically determine the stripe temperature. Temperatures of 1260plusmn90degC for melting and 572plusmn66degC for AFM flip were measured. Temperature for the creation of domains was measured at 603plusmn113 and 516plusmn78degC for forward and reverse bias pulses respectfully. Activation energies of 1.2plusmn.2 and 3.0plusmn.3 eV were observed for resistance changes. Irreversible Magnetic degradation exhibited activation energies of 2.4plusmn.3 eV below and 2.7plusmn.3 eV above about 500degC.