A new method to measure latent heat and electrical conductivity of iron alloys at the pressures and temperatures of planetary cores

Abstract:

Latent heat and electrical conductivity are two material properties that play critical roles in controlling the storage and flow of heat, as well as the flow of electricity inside the planetary cores. We will present new experimental methods that allow measurement of both material properties of metals compressed to high pressures in diamond anvil cells and heated to 1000s of K with pulses of electricity. The method integrates a solid-state switch capable of up to 200 amps with a rise time < 1 microsecond, and a detachable set of easy-to-shape platinum electrodes for four-point-probe measurements. These two technological advances enable heating and electrical measurements that are faster and more reproducible than in past electrical heating experiments while maintaining the large volume of heated sample that is characteristic of internal resistive heating.