Spin-dependent transport in Al grains

and

Single Debye relaxation in BST nanoparticles

Abstract:

In this talk, I will present two topics. For the first topic, we had investigated electron spin transport in nanometer scale aluminum grains as embedded in a ferromagnet tunneling junction. We observed Tunneling Magneto Resistance (TMR) and spin valve effects. TMR strongly exhibits asymmetry with bias voltage. Additionally, we obtained the spin-coherence time of order in nanoseconds by using the Hanle effect. For the second topic, we investigated the dielectric response of BST (high dielectric ferroelectrics) nanoparticles.  The results were found to consistent with Debye relaxation with only a single relaxation time for the dielectric response, and the relaxation time exhibits the Arrhenius law at temperatures below 200K.