Improved Room Temperature Metallic Spin Valves
Sergio O. Valenzuela and M. Tinkham

Spintronics devices, which simultaneously exploit the spin and charge of the electron, are being explored due to promising new electronic applications. Our devices consist of an aluminum strip contacted with two different ferromagnets (FM) with different coercive fields, as shown in the SEM image. Tunnel barriers between the FMs and the Al are grown in situ using a stencil mask and angle evaporation techniques. The Al is 100 nm wide while the FMs are 50nm wide and 150 nm apart, dimensions well below the spin relaxation length of ~300 nm. The measurements show the spin-valve effect at room temperature for positive and negative H-field sweep directions, with ~100 times larger signal than in previous work, largely because of our smaller size.