Giant magnetoresistance effect in la0.8sr0.2mno3 thin films

Abstract

The resistivity and magnetoresistivity behavior of highly oriented La0.8Sr0.2MnO3 thin films have been studied in the temperature range 4.2 K less than or equal to T less than or equal to 300 K, in magnetic fields up to 4.5 T. The films exhibit a temperature-dependent giant magnetoresistance (GMR) effect, with a maximum GMR of the order of similar to 60% in a field of 4.5 T, at 210 K. The temperature dependence of the magnetization shows that the films are ferromagnetic below similar to 200 K. The peak in GMR and zero-field resistivity is observed to lie near the magnetic transition temperature. Our results show that the functional dependence of the magnetoresistivity on the field H, changes from linear at 4.2 K to root H at 210 K. Above the Curie temperature, on the other hand, it shows a H-2 dependence. The resistivity, magnetoresistivity, and magnetization behavior of the present films exhibit a strong correlation as seen through their temperature dependences.