Temperature dependence of magnetocurrent in spin-valve transistor: a phenomenological study

The temperature dependence of magnetocurrent in the spin-valve transistor h as been theoretically explored based on phenomenological model. We find tha t temperature dependence of the collector current strongly depends on the r elative orientation of magnetic moment of ferromagnetic metals due to spin mixing effect. For example, the parallel collector current is decreasing wi th increasing temperatures, while the anti-parallel collector current is in creasing. We then obtain decreasing magnetocurrent with increasing temperat ures. The result accords with the experimental data in qualitative manner. Along with this. we find that temperature dependence of hot electron spin p olarization can also contribute to the magnetocurrent at finite temperature s. This phenomenological model calculations suggest that it is essential to understand the relative importance of spin mixing effect and hot electron spin polarization in the spin-valve transistor at finite temperatures. (C) 2001 Elsevier Science B.V. All rights reserved.