Magnetic and thermal properties of PtMn giant magnetoresistive sensors

The thermal stability of PtMn exchange-biased magnetoresistive heads has been studied. Constant temperature and bias current have been applied, and the amplitude has been measured as a function of time to determine the decay rate and lifetimes. An approach to lifetime data analysis has been developed to estimate the intrinsic sensor temperature and activation energy of the decay mechanism in a self-consistent manner. It has been shown that the internal sensor temperature is higher than the average device temperature determined from the traditional resistance measurements. The method of the lifetime data analysis has allowed the comparison of the activation energy and thermal properties for different types of heads.