Pump-probe optical setup for thermal conductivity measurements in planetary materials

• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: Funded in 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 460605205

The thermal conductivity of planetary materials is a fundamental property that governs the cooling rates and thermal evolution of planetary interiors and hence, their present-day structure and internal dynamics. Yet, the thermal conductivity of candidate materials in deep planetary interiors remains poorly constrained at relevant pressure-temperature conditions, i.e. beyond the Mbar pressure range at several thousand Kelvin. To address this gap in knowledge, new experimental facilities for thermal conductivity measurements applying ultrafast pump-probe optical techniques coupled with diamond anvil cells will be implemented at the Institute of Mineralogy of WWU Münster. At present, however, there is no unique established technique that enables lattice thermal conductivity measurements over the broad range of temperatures of interest, e.g. from 230 K in the interior of small icy bodies to beyond 5000 K in the mantle of rocky/icy (exo)planets. Therefore, two sub-systems based on the Time-domain thermo-reflectance (TDTR) and flash heating techniques will be combined in a unique instrument currently not available at any research institution within Germany or abroad. The new instrument will be central in the research activities of the lead working group for the next decades and will promote interdisciplinary collaborations at the frontiers between geosciences and material sciences. The instrument is intended to provide fundamental new data on the thermal properties of a variety of relevant compounds, including mantle silicates and oxides, iron alloys, melts and planetary icy materials, to further constrain the thermal conductivity of planetary cores, the heat fluxes at the core-mantle-boundary or the thermal evolution of planetary icy bodies, among other applications. In addition, applications to investigate the thermal fluxes in a variety of advanced and functional materials are foreseen in collaboration with material sciences groups at the host institution.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Optischer Pump-Probe-Aufbau für Wärmeleitfähigkeitsmessungen in planetaren Materialien
• Instrumentation Group: 8690 Sonstige Meßgeräte für thermische Größen (außer 860-868)
• Applicant Institution: Universität Münster
• Leader: Professorin Carmen Sanchez-Valle, Ph.D.