Thermal and Electrical Conductivities of Metals and Alloys at Low Temperatures

Abstract

Part [1] On Nickel-Copper Alloys. In order to study the relation between thermal and electrical conductivities of alloys at low temperatures, the conductivities of Ni-Cu alloys were measured at —195° with an improved apparatus. According to the present results the Wiedemann-Franz-Loienz law does not hold especially at low temperatures and for concentrated alloys, and,, the general relation λ = λg+λm = λg + ZmkT+φ (T)k2 holds, which can interprete the results represented by the following experimental formulas, i. e. for dilute alloys w0=w„+ρ /ZmT, w0=-φ (T)/Zm2T2, and for concentrated alloys λ=λ g+ZmkT where Zm is the Lorenz-ratio 5.8×10-9 (cal Ω deg-2) theoretically deduced for the metallic part. The increase of experimental value of Lorenz-ratio for alloys at low temperatures was also.explained from the general equation. The relations between λor k and concentration of the same alloys were also studied. © 1940, The Japan Institute of Metals. All rights reserved.