Selective writing of sub-/spl mu/m/sup 2/ domain in spin valve strip with current coincident scheme

摘要

Cooperative nucleation of sub-/spl mu/m/sup 2/ domains has been performed for a spin valve strip (0.4 /spl mu/m width) of NiFe/Co/Cu/Co overlaid with orthogonal two-layer conductors (write and assist conductors). The current induced MR change due to the write current I/sub w/ markedly increases with the additional assist current I/sub a/. Threshold value of I, required for domain nucleation was decreased from 15 mA//spl mu/m to 9 mA//spl mu/m by the application of I/sub a/ with an amplitude of 10 mA//spl mu/m, which confirms selective writing with the current coincident scheme. The cooperative effect disappears, when the phase difference between I/sub w/ and I/sub a/ becomes larger than the pulse width of 30 ns. Which can be associated with the fast relaxation time of the magnetization process in the sub-/spl mu/m/sup 2/ region.