Precipitation and Low Temperature Resistance in Cu90Co10 Alloys

H. NÚÑEZ COAVAS; G. POZO LÓPEZ; A.M. CONDÓ; J.M. LEVINGSTON; S.E. URRETA; L.M. FABIETTI

Puerto Iguazú, Misiones

Congreso; 13er Congreso SAM - CONAMET, Congreso Internacional en Ciencia y Tecnología de Metalurgia y Materiales; 2013

SAM Asociación Argentina de Materiales

CuCo alloys are a paradigm of granular alloys exhibiting giant magnetoresistance. More recently, a minimum in the electrical resistance has been reported at 35 K [1], which was attributed to a Kondo-like mechanism involving Co rich clusters or precipitates. In this work, Cu90Co10 alloys are prepared by rapid solidification, in a twin roller melt spinning device, at tangential wheel speeds between 5 m/s and 20 m/s, and different solute distributions and Co-rich precipitates size distributions are obtained directly from the melt. The microstructures resulting for different quenching rates are characterized by scanning and transmission electron microscopy, and by X-ray diffraction techniques. Resistance vs. temperature curves are typical of the metallic solids and they show a minimum at low temperature. The precipitation structures observed in the alloys in the as cast condition are correlated with the parameters describing the low temperature resistance minimum. REFERENCES 1. L.M. Fabietti, J. Ferreyra, M. Villafuerte, S.E. Urreta and S.P. Heluani, "Kondo-like effect in magnetoresistive CuCo alloys" Phys. Rev. B. vol. 82, (2010) 172410-14.