Smartlab xrd

Ringvent samples collected at the seafloor by Alvin were studied at UNAM using a transmitted light microscopy (Olympus BX60) coupled with a Motic camera and a low-vacuum Hitachi TM-1000 table-top scanning electron microscope. Stable isotope geochemistry from fibrous aragonite cement samples, and the bivalve shell from Ringvent core P11, were analyzed at UNAM using a mass spectrometer Thermo Finnigan MAT 253 coupled with Gas Bench II, following published guidelines^{59 (link)}. Bulk mineralogy of seafloor samples was determined via X-ray diffraction (XRD) using an EMPYREAN diffractometer equipped with a fine focus Cu tube, nickel filter, and PIXCell 3D detector operating at 40 mA and 45 kV at UNAM. For this, samples were ground with an agate pestle and mortar to <75 μm and mounted in back-side aluminum holders. The analyses were carried out following previously published procedures^{22 (link)}. Phase identification was made with PDF-2 and ICSD databases. Mineral phases from core P11 were analyzed separately with a Rigaku Smart Lab XRD using 0.003° resolution, 5°/minute using a ICDD PDF4+ 2019 database (Ivano Aiello, Moss Landing Marine Laboratory).

XPS spectra were obtained under UHV with a base pressure of 5 × 10⁻⁹ torr on a Kratos Axis Ultra DLD with a monochromatic Al kα source coupled with a hemispherical analyzer. High resolution XPS spectra were baseline subtracted with a Shirley background correction method for subsequent individual peak fitting and peak identification. High coverage HEMG-NP samples were electrodeposited on a glassy carbon rotating disk electrode (r = 2.5 mm) at 1000 rpm and −1.5 V vs. Ag/AgCl and subsequently rinsed with ethanol and water prior to analysis. High substrate coverage was confirmed via SEM prior to surface characterization by XPS. XPS survey scans indicated the presence of characteristic carbon and oxygen peaks consistent with the underlying glassy carbon substrate electrode. XPS survey scans and high-resolution element scans are presented in the supplementary information for two representative quinary HEMG-NP systems indicating the presence of metal oxide species. XPS peak identification of high resolution regions was achieved by comparing binding energy and peak splitting values with standard literature values. These high coverage samples were subsequently analyzed with a Rigaku Smartlab XRD in a 2θ grazing angle orientation to confirm the amorphous microstructure.

For structural characterization, high-resolution X-ray scattering measurements (Grazing Incidence X-ray diffraction and X-ray reflection) were conducted using in-house X-ray diffraction (Smartlab XRD, Rigaku). Transmission electron microscopy (TEM)-ready samples were prepared using the in-situ FIB lift-out technique on an FEI Dual Beam FIB/SEM. The samples were capped with sputtered Ir and e-Pt/I-Pt prior to milling. The TEM lamella thickness was ~100 nm. The samples were imaged with a FEI Tecnai TF-20 FEG/TEM operated at 200 kV in bright-field (BF) TEM mode, high-resolution (HR) TEM mode, and high-angle annular dark-field (HAADF) STEM mode. The STEM probe size was 1-2 nm nominal diameter.

FEI Nova 200 NanoLab DualBeam TM-SEM/FIB was utilized to obtain Scanning Electron Microscopy (SEM) images of the samples. FEI-TITAN microscope operating at an accelerating voltage of 300 kV was used to obtain Transmission Electron Microscopy (TEM) images. X-ray diffraction was collected from 10° to 80° at 5 degree/min scan rate using Rigaku SmartLab XRD with a Cu Kα radiation source. Thermo Scientific DXR Raman Microscope with a 532-nm laser was used for Raman measurements. Kratos X-ray photoelectron spectrometer was employed for XPS measurement. Prior to XPS analysis, the samples were mechanically ground and dried at 80 °C overnight under vacuum. The process of thermal decomposition of pollens were evaluated from 30 °C to 800 °C at 10 °C/min heating rate under constant helium flow (100 ml/s) using a TA DST Q600 thermal gravimetric analyzer. Nitrogen sorption measurement at 77K was conducted using Quantachrome Nova 2200e surface analyzer. Prior to analysis, the samples were degassed at 300 °C for 12 hours.