REX-Optics › REX Analyze

Beta · X‑ray reflectivity · access on request

Understand your XRR data.

Fit thin films and periodic multilayers from an X-ray reflectivity scan. Describe your sample, compare the fitted curve with your data, and download a report of the results and their limitations.

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By REX-Optics, University of Twente spin-off — built for the scans we fit every day.

REX Analyze fitting an X-ray reflectivity curve of an oxide bilayer on silicon Preview of the analysis view. Left: the fitted layer model, silicon dioxide 2.49 nanometres on tantalum pentoxide 30.99 nanometres on silicon, each with an uncertainty, and a quality check marked passed. Right: measured reflectivity points spanning seven decades against grazing angle with the fitted curve through them, and a flat residual strip underneath. REX-Optics · Analyze XRR · Cu Kα · 420 points Correlations Report ⤓ FITTED MODEL SiO2 σ 0.41 ± 0.01 nm 2.49 ± 0.01 nm expected ~1.5 nm Ta2O5 ρ 0.949 ± 0.001 bulk · σ 0.49 nm 30.99 ± 0.01 nm expected ~26 nm Si substrate · σ 0.31 ± 0.01 nm QUALITY CHECK PASS Best solution found by 1 of 15 starts No parameter at a bound All parameters observable in the data A single-start fit would likely miss it REFLECTIVITY 110−210−410−6 res 00.51.0 1.52.02.5 grazing angle θ (°) Measured Fit RMS log residual 0.023 · synthetic benchmark
Example fit to synthetic data: SiO₂ / Ta₂O₅ on Si. This illustration is not a measurement of a real sample.

HOW IT WORKS

From scan to fit

1. Upload your scan

Use an XRDML file or a data table. Preview the curve and Fourier spectrum without using an analysis credit.

2. Describe the sample

Enter the substrate and layers, or use a text description. Approximate thicknesses help; unknown details can stay unknown.

3. Review the result

See the fit, residuals and estimated parameters. If more information is needed, answer within the same analysis. Download the report when it is ready.

WHAT IT CAN TELL YOU

Thickness, density and interfaces

REX Analyze uses AI to choose candidate structures and numerical methods to fit them. It supports single films and periodic multilayers, including structures with caps and barriers.

A close fit does not always identify a unique structure. The report includes quality checks and flags parameters the data cannot resolve. In multilayers, the repeat period can be clear even when individual barrier thicknesses are not.

Which measurement details are needed?

Tables need an angle or q axis and the X-ray wavelength. XRDML files often contain these details. You do not need to know every instrument setting or interface in advance.

How does the Fourier preview help?

Peaks suggest distances between interfaces or a multilayer period. They help initialize the fit; they are not a direct picture of the layer structure. Very thin or low-contrast films may have no reliable peak.

ACCESS AND PRICE

Try it with your own data

Beta access

5 trial analyses

Available by request. Tell us what you measure and which email you would like to use.

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Analysis pack · coming later

€15 / 20 analyses

No subscription. Packs are not available to purchase yet.

One analysis covers one scan and its follow-up questions. Preview is free. Technical failures return the credit; an inconclusive scientific result still counts.

YOUR DATA

Know what you are sharing

REX-Optics stores your uploaded files and reports for 30 days. Your sample description and evidence from the scan are sent to an AI provider for analysis. You can delete your files and reports sooner from your account.

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Send us your sign-in email and a short description of your samples.

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