The spin transport in a lateral spin-injection device with an FeCo/Si/FeCo junction has
been investigated. Magnetoresistance (MR) signals were found to appear at low magnetic fields in
the range 4 300 K. This is attributable to the switching of the magnetization of the two
ferromagnetic contacts in the device for certain magnetic fields over which the magnetization in one
contact is aligned antiparallel to that in the other. Our results suggest that the spin-polarized
electrons are injected from the first contact and, after propagating through the bulk Si, are collected
by the second contact.