Microstructural dependence of electrical transport in bulk CuxGe1x alloys

The electrical transport behavior in bulk processed Cu78.8Ge21.2 and Cu77.4Ge22.6 alloys has been studied as a function of temperature. The room temperature resistivity of the alloy with 21.2 at. % Ge was found to be 4.9 mV cm, an order of magnitude lower compared to the resistivity of the 22.6 at. % Ge alloy. The resistivity of both the alloys is different compared to thin films of equivalent composition which were prepared by a high temperature solid state reaction process. The difference in behavior is found to be due to the microstructure, volume fraction and morphology of the different phases, which depends on the actual method of processing the material