UPITT IVIS High-Temperature FTIR Data (Microfurnace)

This data is related to the following manuscript: Quantitative thermal emission spectroscopy at high-temperatures: A laboratory approach for measurement and calibration. A new microfurnace was developed to heat mineral and rock samples to temperatures between 473 and 1573 K. It was designed to integrate with an existing Nicolet Nexus 670 FTIR spectrometer (with a a liquid nitrogen-cooled mercury cadmium telluride (MCT-B) detector)allowing quantitative emission spectra of samples over the 4000 – 500 cm-1 (2.5 – 20 μm) spectral range during heating and/or cooling. The spectrometer and external experiment chamber (including the microfurnace) are housed within a dry air (H2O and CO2 –scrubbed to less than 1% relative humidity) environment to limit any atmospheric contamination during data acquisition. The new design improves the optical geometry and overall stability of the sample temperature and determination of all downwelling radiance terms, resulting in improved error reduction and less muting of the spectra compared to our previous work (Lee et al., 2013). The data calibration follows the long-used and well-known methodology developed by Ruff et al. (1997). This methodology provides a rigorous procedure for correcting sample measurements and deriving accurate emissivity spectra ( 96%). These were confirmed by comparing the spectra of achieved with the microfurnace to those from the standard emissivity approach (Williams et al., 2019). The quartz sample was acquired from Ward’s Science as ~10 cm long crystals that were analyzed to be 99.9% pure. The forsterite sample was collected from the Newdale olivine deposit located east of Micaville, Yancey County, North Carolina. The bulk rock chemical composition is typically 41.06 wt.% SiO2 with a Fo# of 96.3 (Hunter, 1941). The Hawaiian basalt sample from Kīlauea volcano was collected from the Pu’u Ō’ō episode 61g lava flow on January 30, 2018 (19.34971°N, 155.04752°W). The bulk rock chemical composition is typically 50.8 wt.% SiO2 with a Mg# of 0.38 (Chevrel et al., 2018). The samples were crushed and sieved to 100-350 µm particle size fraction; washed with acetone (to remove clinging fines); and dried in an oven at ~350 K for at least 24 hours. The samples were placed in a platinum crucible as a 2-3 mm thick layer. Sample measurements were acquired at 100 K intervals and can be collected during heating or cooling (or both). An equilibration time of 4-5 minutes is used at each acquisition temperature to ensure the sample is at thermal equilibrium before data was acquired. Eight scans were acquired at each temperature.