  We have performed non-local spin injection into a nano-scale ferromagnetic
particle configured in a lateral spin valve structure to switch its
magnetization only by spin current. The non-local spin injection aligns the
magnetization of the particle parallel to the magnetization of the spin
injector. The responsible spin current for switching is estimated from the
experiment to be about 200 $\mu$A, which is reasonable compared with the values
obtained for conventional pillar structures. Interestingly the switching always
occurs from anti-parallel to parallel in the particle/injector magnetic
configurations, whereas no opposite switching is observed. Possible reasons for
this discrepancy are discussed.
