Strategy and enhanced temperature determination in a laser heated diamond anvil cell

Deemyad, Shanti; Papathanassiou, A. N.; Silvera, Isaac F.

doi:10.1063/1.3117517

Cited by 14 publications

(2 citation statements)

References 14 publications

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“…Emissivity greatly affects the radiative properties of any material and its specific effects on measured temperatures within the laser heated diamond anvil cell have been described extensively in the literature 17,19,20,[24][25][26][27][28][29][30] including specifically its effect on the peak scaling method. 22 Unfortunately, emissivity values (and particularly their dependence on wavelength) are very poorly known for most materials, especially for minerals and rocks (e.g., Touloukian and DeWitt 31 ).…”

Section: B Results: Factors Affecting Fitted Temperaturesmentioning

confidence: 99%

Implementation and application of the peak scaling method for temperature measurement in the laser heated diamond anvil cell

Kunz

Yan

Cornell

et al. 2018

Review of Scientific Instruments

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A new design for a double-sided high-pressure diamond anvil cell laser heating set-up is described. The prototype is deployed at beamline 12.2.2 of the Advanced Light Source at Lawrence Berkeley National Lab. Our compact design features shortened mechanical lever arms, which results in more stable imaging optics, and thus more user friendly and more reliable temperature measurements based on pyrometry. A modification of the peak scaling method was implemented for pyrometry, including an iterative method to determine the absolute peak temperature, thus allowing for quasi-real time temperature mapping of the actual hotspot within a laser-heated diamond anvil cell without any assumptions on shape, size, and symmetry of the hotspot and without any assumptions to the relationship between fitted temperature and peak temperature. This is important since we show that the relationship between peak temperature and temperature obtained by fitting the Planck function against the thermal emission spectrum averaged over the entire hotspot is not constant but depends on variable fitting parameters (in particular, the size and position of the fitting window). The accuracy of the method is confirmed through measuring melting points of metal wires at ambient pressure. Having absolute temperature maps in real time allows for more differentiated analyses of laser heating experiments. We present such an example of the pressure variations within a heated hotspot of AgI at a loaded base pressure of 3.8 GPa.

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Section: B Results: Factors Affecting Fitted Temperaturesmentioning

confidence: 99%

Implementation and application of the peak scaling method for temperature measurement in the laser heated diamond anvil cell

Kunz

Yan

Cornell

et al. 2018

Review of Scientific Instruments

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“…The uncertainties of these temperatures was determined from the standard error on the mean of the fitted temperatures 42 . In the event of poor quality thermal emission from one side of the sample or an unreasonable thermal emission spectra due to "flashing" or a non-convergence of he fit on one side of the sample the uncertainty of the temperature measurement was estimated to be 7% of the fitted temperature as this was determined to be a conservative estimate of the uncertainties associated with this fitting technique 43 .…”

Section: Methodsmentioning

confidence: 99%

High-temperature phase transitions in dense germanium

Kelsall

Peña-Álvarez

Martínez-Canales

et al. 2021

The Journal of Chemical Physics

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Through a series of high-pressure x-ray diffraction experiments combined with in situ laser heating, we explore the pressure-temperature phase diagram of germanium (Ge) at pressures up to 110 GPa and temperatures exceeding 3000 K. In the pressure range 64-90 GPa we observe orthorhombic Ge-IV transforming above 1500 K to a previously unobserved high-temperature phase, which we denote as Ge-VIII. This high-temperature phase is characterised by a tetragonal crystal structure, space group I4/mmm. Density functional theory simulations confirm Ge-IV becomes unstable at high-temperatures and that Ge-VIII is highly competitive and dynamically stable at these conditions. The existence of Ge-VIII has profound implications for the pressure-temperature phase diagram, with melting conditions increasing to much higher temperatures than previous extrapolations would imply.

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Analysis of statistical uncertainties of non-contact temperature and emissivity measurements in the optical and near infrared ranges

Zinin,

Mantrova,

Grishaev

et al. 2024

Measurement

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Strategy and enhanced temperature determination in a laser heated diamond anvil cell

Cited by 14 publications

References 14 publications

Implementation and application of the peak scaling method for temperature measurement in the laser heated diamond anvil cell

Implementation and application of the peak scaling method for temperature measurement in the laser heated diamond anvil cell

High-temperature phase transitions in dense germanium

Analysis of statistical uncertainties of non-contact temperature and emissivity measurements in the optical and near infrared ranges

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