Exchange biasing and low-field magnetoresistance in La0.67Ca0.33MnO3/La0.5Ca0.5MnO3 bilayers

Exchange biasing and magnetoresistance (MR) behaviors have been investigate d in La0.67Ca0.33MnO3/La0.5Ca0.5MnO3 bilayers with specially designed inter facial structures. The exchange coupling is found to be strongly related to interfacial structures. Exchange field H-E decreases as the cooling field N-fc increases at high H-fc region. Especially, the coercivity H-C is enhan ced by exchange coupling for bilayers with rough interface, while it is red uced for relatively smooth interface. Also, large low-field MR has been ach ieved by introducing regular in-plane grain boundaries, and a biasing of R- H loop has been observed.