Preparing your experiment

NOTOS measurements are usually done on 13 and/or 5 mm diameter pellets (XAS) and capillaries (XRD/XAS). Please calculate the linear absorption coefficient μ before preparing your sample. In the case of XAS measurement, we recommend not exceeding 1.5 cm-1 total absorption to avoid distortion and dumping of the EXAFS oscillations. For XRD calculate the relative absorption (μr) at the wavelength (energy) at which patterns will be collected. Note, to minimize absorption correction μr should be <1 (no correction needed) and never higher than 4.5. μr must take into account the packing density (packing fraction, generally 40-60%).

The following web pages and program provide tools to calculate μ:

Quartz and borosilicate capillaries of diameter 0.5, 0.7, 1.0, and 1.5 mm are commonly used at the beamline. Please consider also the wall absorption when preparing your samples:

As a general policy, users need to bring and use their own capillaries to run the experiment. Capillaries can be ordered from several companies like Hilgenberg, WJM-Glas Müller or CTS Capillary Tube Supplies. How to prepare a capillary for operando catalysis experiment? Follow the instructions of the video that you will find below.

The same policy applies for the use of coin cells in electrochemistry experiments. To order your coin cells, please contact Michael Knapp and Almuth Pfleging.

In case of necessity, NOTOS counts on a minimum storage of capillaries and coin cells. In the case of use during your experiment, you need to return number of pieces used in the shortest time.

Please contact the local contact and try to coordinate with her/him to avoid any change of setup and/or configuration outside the standard working hours.

Data treatment on the beamline can be performed using standard programs like:

Athena (https://bruceravel.github.io/demeter/)
GSAS (https://www.aps.anl.gov/Science/Scientific-Software/GSASII)

while a fast data reduction and visualization can be done using the Fast data Analyser (FDA) a Python utility written by C. Marini, oriented to the analysis of X-ray absorption spectra and XRD patterns. A paper is in preparation. The latest version of the code (0.9.3) can be downloaded at this link: https://git.cells.es/cmarini/fda_free/-/blob/master/fda_free.093.7z . Please read the file "README.TXT" to install and run the program.

Here you will find the reference to the FDA code: C. Marini and S. Toutounchiavval 2025 J. Phys.: Conf. Ser. 3010 012117 DOI 10.1088/1742-6596/3010/1/012117

Sample environments

Capillary setup

Quartz capillary setup available at PD-XAS station. Temperature controlled with a hot air blower, and a maximum pressure of 20 bar

Temperature control for capillaries

FMB Oxford hot air blower

Temperature range: RT – 1223K (RT – 900°C).

To be used with samples in capillaries (quartz ones for temperatures above 700°C).

Detailed description of the equipment can be found at the manufacturer's website.

Self-supported pellet cell for gas and temperature experiments

In situ measurements will be perfomed by a cell already in use at SpLine beamline at ESRF. This cell will allows measurement on sample in self supported pellet form in trasmission configuration. The maximum working temperature is 500˚C at ambient pressurfe.

J-cell for gas and temperature experiments

In situ measurements can be performed on pellet samples in transmission and fluorescence configurations. The maximum working temperature is 550 °C and the maximum pressure is 20 bar.

Coin cells setup

A setup for measuring four coin cells simultaneously is available, connected to a four-channel BioLogic VSP potentiostat/galvanostat

Electrochemical cell

A commercial Nonlinear Spectro-Electrochemical Flow Cell from Redox.me is available.

Gas experiments

Reactive Gas System

Since NOTOS is highly devoted to Catalysis, in situ processes and other dynamic characterization of materials, an integrated, user-friendly and versatile reactive gas system is available.

The available gas lines are the following:

Nr	Gas^*	Max Flow (ml/min)	P range (bar)^**
1	Hydrogen	50	Patm - 20
2	CO	50	Patm - 20
3	Methane, ethane, propane	50	Patm - 20^***
4	Ethylene, propylene	50	Patm - 9^****
5	He	200	Patm - 20
6	Ar	10	Patm - 20
7	CO₂, N₂	50	Patm - 20
8	Oxygen 20%	50	Patm - 20
9	NO ≤ 2%; NO₂ (+21% O₂) ≤ 0.5%; N₂O ≤ 36%	50	Patm - 5
10	NH₃ ≤ 25%	50	Patm - 5

*: For not dedicated gas lines, gas for calibration is indicated in bold letters. All dilutions are done in He.
**: No pressure control from Patm to 4bar. In a second stage of the gas system design it is planned to implement a back-pressure controler up to 80 bar.
***: Up to 6 bar for propane
****: Up to 8 bar for propylene

A bubbler for injecting vapours is also available, restrited to work at atmospheric pressure and with a limited list of liquids. Please, contact the beamline staff for further details.

A MKS Cirrus 3XD gas analyzer is also available. For additional information, doubts or suggestions please contact the beamline staff.

Instrumental resolution

Angular dependence of the peak FWHM for different capillary diameters at the DIF-XAS end station is shown. Measurements were performed at 23 keV using the Mythen detector (sample-to-detector distance of 535 mm). The curves are illustrative and provided for comparison purposes.

The instrumental resolution is angular-resolution dependent. Powder diffraction patterns on a standard LaB6 (NIST standard 660b) were collected for this purpose. Cagliotis coefficients for the two main energies at NOTOS are reported below. These are starting points for your fit. We recommend taking a LaB6 pattern at the time of your experiment with the actual setup to improve the fit's precision.

* FullProf parameters are used directly from the table. GSAS ii represents the values using a format (value x10^-3) e.g. U = 3.861