Resistivity and magnetoresistance studies on RCoGe3 (R = La, Ce) compounds

Resistivity (rho) and magnetoresistance (Delta rho/rho(0)) have been measur ed for polycrystalline LaCoGe3 and CeCoGe3 compounds. The temperature depen dence of rho for the La compound is described by rho proportional to T-3 fo r T much less than theta(D) and proportional to T at high temperatures. At 4.5 K a significantly large Delta rho/rho(0)(similar to 1) is observed. In CeCoGe3 rho(T) exhibits a sharp drop below the magnetic ordering temperatur e, 21 K. In the antiferromagnetic region between 4 and 16 K it follows a qu adratic temperature dependence. The magnetic contribution to resistivity, r ho(m), exhibits a maximum at similar to 125 K above which it decreases foll owing a logarithmic temperature dependence. The magnetoresistance remains p ositive for temperatures between 4.5 and 30 K but shows field induced trans itions at similar to 7 kOe and similar to 28 kOe.