Energy Dispersive XAFS (DXAFS) Measurement Equipment

◆Equipment overview

This system consists of equipment that can measure the entire range of the XAFS system at once, using curved analyser crystals and position sensitive detectors. Time-resolution measurements on the millisecond order are possible.

◆Features of the Equipment

This system is a visible light conversion 2-dimensional detector which is configured with a high-harmonic removal mirror and polychromators. There are two types of polychromators, a Bragg polychromator used for the low-energy region of roughly 7～12keV, and a Laue polychromator for high energy regions. The light collection size at the sample position is between 20-200μm laterally.

Visible Light Conversion 2-Dimensional Detector
A visible light conversion 2-dimensional detector is available as a detector for this system. Fluorescent substances are mainly available with the high conversion efficiency P43（Gd₂O₂S:Tb³⁺）, and the 2-dimensional detector C4880-80 manufactured by Hamamatsu Photonics, or the high-speed measurement range Orca Flash also manufactured by Hamamatsu Photonics.

Control Software
Equipment control and XAFS measurements are performed using a program made by LabVIEW, which is manufactured by NI. Sample environment control (temperature, opening and closing of the gas valves, etc) and XAFS measurements can be performed in tandem.

◆Equipment accessories

●Transmission in-situ gas flow heating cell
　Temperature range: Room temperature ～　1073K
●Batch high-speed gas replacement system
　Temperature range: Room temperature ～　973K
　Pressure: 0.1Pa　～　101.3kPa
　Pressure gauge response: <5msec
　Temperature response: 100ms
●Mass flow control
　He：300ml/min、H₂:10ml/min，O₂：50ml/min, CO：10ml/min,
　NO：10ml/min
●Gas mixing system
　Maximum number of gasses: 4
●4 Heavy pole mass spectrometer (～100amu）* shared with BL01B1
●Gas supply and abatement equipment
　Inflammability: 2 systems
　Flammability：2 systems
　Available gasses (processed): He，H₂，O₂，HC，CO，NO, NH₃

◆Experiment / sample preparation

It is recommended that the composition of the sample be analysed by ICP emission analysis before being brought in. It is also recommended that you use calculation software such as XAFS Sample Preparation Guide Program (Industrial Use Promotion Office) or something similar to calculate the amounts required for measurements and sample preparations.

◆Experimental procedure / precautions

①Measure the standard samples to perform energy calibration.
②Assemble the in-situ gas flow heating cell and gas plumbing around the sample.
③Place the sample in the X-ray center by using the automated stage to adjust the position of the sample.
④Use the detector control program to adjust the detector exposure time.
⑤Complete in-situ measurements using a measurement program suitable for in-situ measurements.

◆Contact

加藤和男 このメールアドレスはスパムボットから保護されています。閲覧するにはJavaScriptを有効にする必要があります。

◆List of representative treatises

"Time Resolved in situ DXAFS Revealing Highly Active Species of PdO Nanoparticle Catalyst for CH₄ Oxidation"
Mahara Yuji
ChemCatChem, 10, (2018) 3384-3387
DOI : 10.1002/cctc.201800573

"Striking Oxygen-Release/Storage Properties of Fe-Site-Substituted Sr₃Fe₂O_7?δ"
Beppu Kousuke
The Journal of Physical Chemistry C, 122, (2018) 11186-11193
DOI : 10.1021/acs.jpcc.7b12754

"In situ X-ray Absorption Spectroscopy Study on Water Formation Reaction of Palladium Metal Nanoparticle Catalysts"
Matsumura Daiju
International Journal of Hydrogen Energy, 42, (2017) 7749-7754
DOI : 10.1016/j.ijhydene.2016.08.189

"Hydrogen-Mediated Electron Doping of Gold Clusters As Revealed by In Situ X-ray and UV-vis Absorption Spectroscopy"
Ishida Ryo
The Journal of Physical Chemistry Letters, 8, (2017) 2368-2372
DOI : 10.1021/acs.jpclett.7b00722

"In Situ and Real-Time Monitoring of Oxide Growth in a Few Monolayers at Surfaces of Platinum Nanoparticles in Aqueous Media"
Imai Hideto
Journal of the American Chemical Society, 131, (2009) 6293-6300
DOI : 10.1021/ja810036h