Elastic constants and electrical resistivity of Fe3Si

Abstract

The electrical resistivity and elastic constants of slowly cooled single-crystal specimens of the ordered alloy Fe3Si (cubic, DO3 structure) were measured from 4.2 °K to room temperature. The residual resistivity (ρo) was determined to be 0.6 μΩ cm. We infer from this that had the composition been exactly stoichiometric, which it was not, and the crystal free of internal voids generated during growth from the melt, the ρo would have approached zero—a behavior that has not been reported previously for a (non-superconducting) long-range ordered alloy. The temperature dependences of the directly measured adiabatic elastic constants were found to be as follows (uncorrected for thermal contraction; T in °K): CL(T) ={3.410−0.2696/[exp(367/T)−1]}×1011 N/m2; C (T) ={1.405−0.0563/[exp(227/T)−1]} ×1011 N/m2; C′ (T) ={0.4183−0.1132/[exp(393/T)−1]}×1011 N/m2. Calculated values for the isothermal Young’s modulus (E), the shear modulus (G), and the Poisson ratio (ν) of a polycrystalline aggregate of Fe3Si possessing a random distribution of crystallite orientations are, for T=295 °K, as follows: E=2.15×1011 N/m2, G=0.828×1011 N/m2, and ν=0.299. The Debye temperature of the alloy at 0 °K is 501.1 °K.