Effect of organic spacer in an organic spin valve using organic magnetic semiconductor V[TCNE](x)

We studied the role of organic semiconductor spacer tris (8-hydroxyquinoline) (Alq(3)) in a hybrid spin valve which is comprised of V[TCNE](x) (x similar to 2, TCNE: tetracyanoethylene) and Fe as the ferromagnetic layers. We compare two types of devices: Fe/V[TCNE](x)/Al and Fe/Alq(3)/V[TCNE](x)/Al, showing that organic spacer is not indispensable for the appearance of the spin valve effect. However, the device with Alq(3) spacer has magnetoresistance (MR) value one order of magnitude larger than the device without spacer. The MR of both devices diminish with increasing temperature, while only the Fe/Alq(3)/V][TCNE](x)/Al device shows room-temperature MR.close3