We proposed the control of the domain-wall-nucleation process by injection of the spin-polarized current into the wire end of the ferromagnetic wire via the nonmagnetic material, and attempted to observe the change of the switching field due to the spin injection in two-type planar-configuration devices. In one device using focused ion beam (FIB) in situ etching, the changes of the switching field, which were consistent with the spin-injection model, were very small. This may be because the irradiation effects induced by the FIB etching modify the properties of the ferromagnetic wire near the etched region. In the other device using multi-angle deposition, the clear changes of the switching field were observed and were quantitatively consistent with the model based on the spin-transfer effect. The interface fabricated by the multi-angle deposition may be useful for forming the ideal ferromagnet/nonmagnet interface.