EXAFS spectroscopy

Knowledge graph centered on EXAFS spectroscopy with 38 nodes and 127 connections. Top connected: Gothic, Crested Butte, Pekania pennanti, Colorado East River Valley, Potentilla gracilis.

Method synopsis

Extended X-ray absorption fine structure analysis of Fe-bearing colloids using synchrotron radiation with cryogenic sample preparation and shell-by-shell fitting to determine molecular coordination environment.

Synthesized from method descriptions across 3 papers using this protocol.

Procedure from a recent peer-reviewed implementation

Steps below were extracted from the most recent peer-reviewed implementation of this protocol in the corpus — X-ray chemical imaging for assessing redox microsites within soils and sediments (2024), Frontiers in Environmental Chemistry. Implementations in other papers (listed below) may differ.

1. Perform μ-XRF mapping
   Multiple energy μ-XRF maps were collected at 7,116, 7,123, 7,127, 7,132, 7,138, and 7,145 eV at ambient temperature using a 4-channel Vortex Silicon Drift detector. The map step size was 30-75 μm with a dwell time from 25 to 50 ms. The angle subtended by the incident beam, sample, and detector was 90°, with the sample normally bisecting this arrangement.
   Quantities: Energies: 7,116, 7,123, 7,127, 7,132, 7,138, 7,145 eV; Step size: 30-75 μm; Dwell time: 25-50 ms; Angle: 90°Duration: 25-50 ms per pixelConditions: Ambient temperature, 90° geometry
   Equipment: 4-channel Vortex Silicon Drift detector, Stanford Synchrotron Radiation Lightsource beamline 2-2

Typical Equipment

• 30-element germanium detector
• Stanford Synchrotron Radiation Lightsource beamline 7-3
• Kapton tape

Output Measurements

• Fe coordination environment
• interatomic distances
• coordination numbers
• phase identification

Papers Using This Protocol (3)

Species Studied With This Protocol

Places Where Used