"Sub-Microsecond Pulse Heating Measurements of High Temperature Electrical Resistivity of the 3d-Transition Metals Fe, Co, and Ni"

Abstract

The exploding wire technique is suitable for the determination of the electrical resistivity of metals in a wide temperature range provided that the heating of the wire material in the liquid phase occurs fast enough to avoid changes in the wire geometry due to surface tension. It is also an appropriate method for measuring latent heats of fusion especially for refractory metals. The electrical resistivity ρ and the enthalpy H are derived from time-resolved measurements of cur­ rent and voltage of exploding wires, which are part of a fast RCL-discharge circuit. The time interval for heating the wire from room temperature to the normal boiling point is typically 1 μsec. Because of the short times involved interactions with the surrounding medium are negligible. The time resolution of the system is better than 8 nsec and the estimated error of measured resistivity and enthalpy above temperatures of 1000 K is less than 4%. For Fe, Co, and Ni the ρ (H) -dependence up to the normal boiling point and the therefrom derived ρ (T) -dependence are reported and compared with steady-state experiments.