Angular dependence of spin torque critical currents for CPP-GMR read heads

作者：Smith N^*; Katine JA; Childress JR; Carey MJ

来源：IEEE Transactions on Magnetics, 2005, 41(10): 2935-2940.

DOI：10.1109/TMAG.2005.855314

• current perpendicular-to-plane (CPP)
• giant magnetoresistance (GMR)
• read head
• spin-torque

This paper employs (analytical) micromagnetic modeling to derive expressions for the critical current at the onset of spin-transfer-torque (STT) instability in CPP-GMR read heads,,as a function of the relative angle between the free and reference layer magnetizations, including a general angular dependent STT coefficient. Experimental measurement of the angular dependence of the critical currents are made on 50-nm-sized CPP-GMR devices with synthetic antiferromagnet pinned layers, and fabricated using e-beam lithography. The results are consistent with prior theoretical models, but indicate perhaps unanticipated implications for read head operation.

• 出版日期2005-10