Development and Fabrication of High Temperature and Low Field Colossal Magnetoresistance (CMR) Materials

Sean Li, Peter Hing and Yuebin Zhang

Advanced Materials Research Center

Division of Materials Engineering, School of Applied Science

Nanyang Technological University, Singapore 639798

Sponsored by ITS Science and Medical Pte Ltd

Colossal magnetoresistance materials (CMR) developed in 1994 promise to increase the sensitivities of the hard disk drive (HDD) heads by orders of magnitude over today’s state of the art. In present work, the room temperature CMR materials have been successfully fabricated. It is needed to study the mechanism further to solve the low field problem. With SEM, XRD and DSC advanced techniques, the surface morphologies and grain growth behaviors, lattice structures and Curie temperatures have been investigated. The real lattice structures have been located to determine the Mn-O-Mn bond angle which is the key factor of Curie temperatures. The DSC technique has been successfully used to measure the paramagnetic insulator-ferromagnetic metal transition which is closely associated with Curie temperatures.