  Proximity effect of spin orbit coupling is investigated through anomalous
Hall effect in Pt/Co2FeAl and Pt/Permalloy bilayers. A series of nontrivial
magnetotransport behaviors, resulting from a strong impact of phonons on skew
scattering, is observed in these films with ultrathin ferromagnetic layers. The
parameters representing skew scattering, side jump and intrinsic contributions
are dramatically enhanced when the ferromagnetic layer is very thin, and they
have clear linear dependences on the reciprocal of ferromagnetic layer
thickness, indicating a powerful influence of Pt/Ferromagnet interface. Further
study on Cu/Co2FeAl and Ta/Co2FeAl bilayers reveals that a simple interface
scattering without intense spin orbit coupling is not sufficient to trigger
such a phenomenon. The proximity effect of spin orbit coupling is thus
suggested to occur at the Pt/Ferromagnet interface, and as a result quite large
anomalous Hall angle (0.036) and Nernst angle (0.23) are confirmed in the
Pt/CFA films at room temperature.
