  To elucidate the spin relaxation mechanism of SrNbO3 (SNO) ultrathin films,
the transport properties of a series of SNO films with various thicknesses were
measured on both sides of the metal insulator transition. The spin orbit
scattering time was deduced from the analysis of the magnetoresistance with
weak antilocalization theory, and it was found that the spin orbit scattering
time was inversely proportional to the momentum scattering time. This result
was explained in terms of the D`Yakonov Perel` mechanism, indicative of the
dominant Rashba effect. The values of the Rashba parameter were largest in the
values reported for other ultrathin films of metallic oxides.
