Magneto Restrictive Sensor*

Magneto restrictive based sensors can be used for diagnosis and prognosis of cracks and creep in vital parts of several mechanical systems. One material studied extensively for this application is Tb_0.3Dy_0.7Fe₂ (TFD). We studied the structural and magnetic properties of micro-particles of TFD embedded inside reinforced carbon fiber polymer (RCFP) using VSM, TMM and MFM. Results show enhanced magnetic properties for TFM when embedded inside RCFP and a two-fold magnetic symmetry. To get a deeper understanding of the structural and magnetic properties of TFD, thin films were synthesized using magnetron DC/RF sputtering. Study of surface magnetism of films processed at a substrate temperature of 250 ^oC using MOKE revealed a four-fold magnetism. Results from magnetic and structural measurements will be presented.