The combination of extreme pressures and temperatures permits access to low-energy configurations and metastable states in condensed matter. In the lab, these extreme conditions can be achieved by applying laser heating in the diamond anvil cell (LH-DAC). This highly tunable, controlled experimental approach provides a powerful tool to alternative states, control of reaction pathways, and insight into the behavior of materials up to the most extreme conditions found in planetary interiors and beyond.
HiPSEC hosts a number of dedicated laser heating systems for high-pressure high-temperature experiments. Since different materials can exhibit a vast variety of electronic properties, different energies of laser light are necessary to allow direct coupling with materials. The HiPSEC laser heating table is thus equipped with a combination of single-sided CO2 laser heating, which operates at 10.6 µm and is directly absorbed by a large range of wide bandgap insulators and semiconductors, and double-sided ytterbium-doped fiber system, operating at 1070 nm, specific for metals and narrow bandgap semiconductors.
In addition to generating high-temperature conditions, one of the big challenges lies in accurately measuring and reliably determining sample temperatures. We are currently developing spectrometric temperature analysis methods that include 2D color mapping, thermal emission measurements into the mid-infrared, and high-temperature Raman spectroscopy system to allow an alternative to traditional pyrometry.