Laufenberg M, Bührer W, Bedau D, Melchy P-E, Kläui M, Vila L, Faini G, Vaz C A F, Bland J A C, Rüdiger U
Fachbereich Physik, Universität Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.
Phys Rev Lett. 2006 Jul 28;97(4):046602. doi: 10.1103/PhysRevLett.97.046602. Epub 2006 Jul 25.
We present an experimental study of domain wall motion induced by current pulses as well as by conventional magnetic fields at temperatures between 2 and 300 K in a 110 nm wide and 34 nm thick Ni80Fe20 ring. We observe that, in contrast with field-induced domain wall motion, which is a thermally activated process, the critical current density for current-induced domain wall motion increases with increasing temperature, which implies a reduction of the spin torque efficiency. The effect of Joule heating due to the current pulses is measured and taken into account to obtain critical fields and current densities at constant sample temperatures. This allows for a comparison of our results with theory.
我们展示了一项实验研究，该研究针对在110纳米宽、34纳米厚的Ni80Fe20环中，温度介于2开尔文至300开尔文之间时，由电流脉冲以及传统磁场引起的磁畴壁运动。我们观察到，与磁场诱导的磁畴壁运动（这是一个热激活过程）不同，电流诱导磁畴壁运动的临界电流密度随温度升高而增加，这意味着自旋扭矩效率降低。测量并考虑了电流脉冲引起的焦耳热效应，以获取在恒定样品温度下的临界场和电流密度。这使得我们能够将结果与理论进行比较。
