Evidence for Weak Localization and Spin Orbit Scattering in CoSi sub 2 Films

The temperature dependent Resistance and Magneto- resistance of 2 nm- 20 nm thick CoSi sub 2 films have been measured to a temperature of 200 mK. A log T dependent resistivity is observed for all films in this range of thickness, and whose coefficient is consistent with that of weak localization. We observe a reduction of Tc in these films and complete suppression for thickness less than 84angstroms. Careful magnetoresistance measurements reveal for the first time a low field positive magnetoresistance consistent with strong spin-orbit scattering. The low field magnetoresistance is also anisotropic, which is characteristic of the weak localization description. The films were fabricated by J.M. Phillips at AT&T.