Frequently asked questions

Get in touch if you have more questions

What is this service?

Momentum Transfer offers a mail-in service for high-quality and high-throughput synchrotron X-ray powder diffraction measurements. You mail us your samples; we perform the measurements and send you the results.

When are measurements performed?

Beamtimes are regularly pre-arranged, meaning that there are no long waiting times for access to measurements. We'll inform you through the platform of upcoming beamtimes so that you can mail-in your samples in time. Compared to other methods of paid access, there is no minimum number of samples or shifts that must be purchased by the customer. Additionally, we provide data reduction and validation of results to ensure accuracy, including processing total scattering data to obtain pair distribution functions.

Which measurement modes are available?

When you setup your measurement request in the portal, you can choose between, high-resolution powder XRD (HR-XRPD), total-scattering pair distribution function (TS-PDF) analysis and small angle scattering measurements (SAXS).

How many samples can I measure?

If you want to carry out a large-scale investigation, no stress. We can readily handle thousands of samples in a shift, and our regular shift schedule is great for scheduling consecutive sample batches.

What is the result of my measurements?

After the measurements are performed, we take care of the post-processing of the detector images this includes: data reduction, integration, offset correction, background subtraction. Once, the post-processing is complete you'll find raw data, corrected data, reference measurements, detector settings and a report in your account for inspection and download.

What consultation services are available?

We assist users in various scientific endeavors. We can help determine the optimal measurements needed to solve their scientific problems and provide guidance on data interpretation to help users make sense of their findings. We specialize in performing structure refinement, utilizing methods such as Rietveld or real-space refinement. Furthermore, we have experience in determining various sample properties such as phase contents, impurities, crystallite size, bond lengths, and domain size in disordered materials. Our assistance also extends to aiding with crystal structure determination, including unit cell indexing, simulated annealing, reciprocal- and real-space co-refinements. Lastly, we offer statistical analyses for large datasets, allowing for in-depth exploration of the data.

Which methods do you support?
  • Phase identification
  • Rietveld refinement
  • Phase quantification
  • Unit cell indexing
  • Crystal structure solution via simulated annealing
  • Real space structure refinement
  • Structure mining for local structure analysis
  • Cluster mining for assessment of small nanoparticle distributions
Which payment methods do you accept?

We will provide a quotation on the desired services. Invoices for services can be paid by bank transfer within 30 days. We can also support payment via credit card.

Use of results?

Our services are suitable for both commercial and academic purposes. Customers own the rights to their results.

What are benefits of high-energy X-rays?

Increasing sample transparency at higher energies allows for using thicker samples to probe larger sample volumes. Minimal correction is needed for absorption or fluorescence for most elements. At 75 keV, consideration of fluorescence effects may be necessary for samples containing higher lanthanides up to Os, especially for total scattering data.

What is the geometry of the experiment?

The experiment is setup in transmission geometry using a 2-dimensional detector. The setup is useful to reduce preferred orientation effects and to obtain symmetric line profiles.

Process

How do I get access?

You create an account for the platform, where you manage your measurement requests, samples and measurement results. The portal is growing continuously as we are adding valuable features for the inspection and analysis for powder diffraction data.

How can I make a measurement request?

Registering samples and submitting measurement requests is simple through our online portal. Create an account to start defining your samples. For large volumes, download a CSV template for easy data entry and batch import (Samples → Import → Download CSV template). Once your samples are ready, select them and create a measurement request. Choose the measurements you need, add any custom messages, and include tracking information for your shipment. Then, simply submit!

How should I send samples?

When preparing filled sample holders for shipment, please use stiff packaging with ample padding to prevent breakage during transit. Ensure the sample holder is secure, avoiding any movement, torque, or bending. Additionally, use extra containment to safeguard against possible leakage. To help us easily identify your samples, include a sample list along with any special handling instructions. If you are shipping samples from outside the European Economic Community (EEC), customs may require additional documentation, specifically a pro forma invoice for the shipment. We can provide an example on request.

Are there any restrictions on the type of samples?

The measurements offered are only suitable for powdered samples, not single crystals. We can also work with polycystalline solids such as plastics or alloys, semisolids such as gels, creams, pastes, etc, and have even measured films deposited on substrates. Our current sample holders are not fully sealed against oxygen or moisture, so we advise against sending samples that are highly sensitive to air or humidity. We are working on improvements to accommodate these needs. We are unable to handle liquids, gases, biological samples (e.g., animal tissues), or any dangerous materials: including samples that are poisonous, biological, radioactive, explosive, carcinogenic, mutagenic, reprotoxic (CMR), highly reactive, unstable, or pose other significant hazards.

How do I get my data?

Data are provisioned through our online portal. Before coming to you we take take of all the steps in between including calibration of the experimental setup, image correction and integration, data standardization, background subtraction, and transformation. Data are received in a ready-to-use state.

Experiment Specifications

High-resolution X-ray powder diffraction (HR-XRPD)
Detector Distance ~1.5 m
Q-range ~0.16 – 9.1 Å-1
d-spacing 40 – 0.69 Å
Peak resolution ~0.004 Å-1 (determined from first peak integral breadth)
Total scattering (TS)
Detector Distance ~0.3 m
Q-range ~0.32 – 31 Å-1
d-spacing 20 – 0.2 Å
Peak resolution ~0.02 Å-1
Pair distribution function (PDF)
Usable Q-max ≤20 - 30 Å-1 (depending on material)
Real space Δd approx. ≥0.16 – 0.11 Å (determined as π/Qmax)
Maximum distance ≤250 – 300 Å
Small-angle X-ray scattering (SAXS)
Detector Distance ~8.9 m
Q-range ~0.01 – 0.37 Å-1
d-spacing ~630 – 17 Å

Data Quality

Data Quality
Sharp and symmetric instrumental profile

Superior Quality

Using high energy X-rays (75 keV) and highly monochromatic radiation combined with 2D detection results in a sharp and symmetric instrumental profile which is ideal for detecting low-intensity features, decomposing overlapping features, and distinguishing microstructural properties.

Example Data

Nano-crystalline calcium carbonate

X-ray diffration pattern of nano-crystalline calcium carbonate
X-ray powder diffraction pattern
X-ray diffration pattern of nano-crystalline calcium carbonate
Total scattering
X-ray diffration pattern of nano-crystalline calcium carbonate
Pair distribution function

Amorphous organic polymer

X-ray diffration pattern of nano-crystalline calcium carbonate
X-ray powder diffraction pattern
X-ray diffration pattern of nano-crystalline calcium carbonate
Total scattering
X-ray diffration pattern of nano-crystalline calcium carbonate
Pair distribution function