Hydrogen concentration analysis in clinopyroxene using proton–proton scattering analysis

Abstract

Traditional methods to measure water in nominally anhydrous minerals (NAMs) are, for example, Fourier transformed infrared (FTIR) spectroscopy or secondary ion mass spectrometry (SIMS). Both well-established methods provide a low detection limit as well as high spatial resolution yet may require elaborate sample orientation or destructive sample preparation. Here we analyze the water content in erupted volcanic clinopyroxene phenocrysts by proton-proton scattering and reproduce water contents measured by FTIR spectroscopy. We show that this technique provides significant advantages over other methods as it can provide a three-dimensional distribution of hydrogen within a crystal, making the identification of potential inclusions possible as well as elimination of surface contamination. The sample analysis is also independent of crystal structure and orientation and independent of matrix effects other than sample density. The results are used to validate the accuracy of wavenumber-dependent vs. mineral-specific molar absorption coefficients in FTIR spectroscopy. In addition, we present a new method for the sample preparation of very thin crystals suitable for proton-proton scattering analysis using relatively low accelerator potentials.

Low-Frequency Noise in Electric Double Layer InGaZnO Thin-Film Transistors Gated with Sputtered SiO2-Based Electrolyte

“…This degradation is related to the reduced number of protons inside the gate electrolyte. The proton content might be detected through methods such as Fourier transformed infrared (FTIR) spectroscopy, secondary ion mass spectrometry (SIMs), and proton–proton scattering . In this study, the performances of the TFTs under different moisture conditions were compared to reflect the behavior of the moisture-induced protons.…”

“…The proton content might be detected through methods such as Fourier transformed infrared (FTIR) spectroscopy, 26 secondary ion mass spectrometry (SIMs), 27 and proton−proton scattering. 28 In this study, the performances of the TFTs under different moisture conditions were compared to reflect the behavior of the moistureinduced protons. After removal of moisture though heat treatment, the number of the moisture induced mobile ions is reduced, 12 and the capacitance generated by EDL decreases, resulting in a decrease in the on-current and an increase in the threshold voltage.…”

Mantle metasomatic influence on water contents in continental lithosphere: New constraints from garnet pyroxenite xenoliths (France & Cameroon volcanic provinces)

“…the mineral-dependent calibration of Bell et al (1995; using integral specific absorption coefficients l′ Cpx = 7.09 ± 0.32 and l′ Opx = 14.84 ± 0.59 for clino-and orthopyroxene, respectively) and the wavenumber-dependent calibration of Libowitzky and Rossman (1997; using mean wavenumbers ν Cpx = 3550 cm −1 and ν Opx = 3500 cm −1 ). For diopside, the wavenumber-dependent calibration is considered to be more reliable than the mineraldependent calibration (Weis et al, 2018). However, the mineral-dependent calibration was developed using natural minerals similar to those analyzed herein and is thus particularly suitable for our purposes.…”

Determination of hydrogen concentration in solids by transmission ERDA under nuclear-elastically enhanced recoiling of H by 8 and 9 MeV He

“…At about the same time, elastic recoil coincidence spectroscopy (ERCS), which is a variation of T-ERDA, has been developed [10]. Later, ERCS using proton-proton scattering was applied to observe the fluid inclusion in minerals [11], localized H distribution in diamond [12], and H density in clinopyroxene crystals [13]. In the studies mentioned above, the workers obtained higher spatial resolutions than for the typical case of neutron tomography [14], which is a competitive analysis technique with ERDA.…”