Development of recording technology with FePt recording media and magnetic tunnel junction sensors with conetic alloy

Abstract

With highly demanding requirement in current emerging cloud storage and personal computers, hard disk drive recording with high stability and high volume has attached much attention in industry and academy. Recording media and recording head feasible for future high-density recording are both crucial to utilize magnetic recording with 1T bit/in2 recording density. Recoding media with FePt for high density and high stability was investigated in this thesis using FePt polymers with imprinting methods and FePt thin films with ion-beam bombardment technologies. The FePt polymers can be patterned using imprint at micro-and nano-scales. The micro-and nano-patterns could be retained on substrates after sintering at high temperatures. The high magnetic coercivity was proved with line and dot patterns at different scales. Recording heads with Al2O3based magnetic tunneling junction sensors were also studied in thesis. The magnetic tunneling junction sensors were proved to work stable at different temperatures varying from -30oC to 100oC. The long time running test up to 100 hours also proved the stability of the magnetic tunneling junction sensors working in extreme temperatures. Withstate-of-art patterning and depositing technologies, new ideas about using FePt polymer to work as magnetic recording media and using ion beam bombardments to tune the FePt magnetic properties were verified. The feasibility of using Al2O3 based magnetic tunneling junction sensors as recording head was also discussed.