Combinatorial Materials Discovery · Bochum, Germany

342 compositions.
One wafer.
One campaign.

xemX operates a high-throughput combinatorial PVD platform producing 342 unique thin-film compositions per campaign with fully automated characterization at every composition point. If you have a multi-element material problem and the composition space is too large to navigate sequentially, we map it.

342 unique compositions per campaign
8 co-sputtering cathodes, simultaneous
36 elements available
Platform

Built for systematic exploration
of multi-element spaces.

The platform produces a continuous composition gradient across up to eight elements simultaneously. Every point in that gradient (342 on a 100mm wafer) is characterized for the properties relevant to your application. The result is a composition-property map: a dataset showing where in the element space your required properties exist, and how those properties change as composition shifts.

This is structurally different from sequential material evaluation. Conventional approaches test one composition at a time. The xemX platform tests the entire space at once.

DepositionMagnetron co-sputtering, 8 cathodes simultaneous. DC, RF, pulsed DC, and reactive sputtering (N2, O2). Covers metals, nitrides, and oxides.
Substrate100 mm wafers
Compositions342 unique points per campaign, continuous gradient
Composition mappingEDX / WDX automated scanning
Phase mappingAutomated XRD at each composition point
MechanicalNanoindentation: hardness and elastic modulus
Electrical4-point probe: sheet resistance / resistivity
ElectrochemicalScanning Droplet Cell: activity, stability, corrosion potential
OpticalReflectance spectroscopy (UV-VIS)
MagneticMOKE: magnetic property mapping
OutputFull composition-property maps, structured dataset delivery
Applications

Open problems the platform
is built to address.

Every application involves a multi-element composition space where the target properties are known but the optimal composition is not.

Green Hydrogen
Electrolyzer Catalysts & Bipolar Plate Coatings

OER and HER catalyst composition spaces mapped for activity, stability, and PGM loading tradeoffs using the Scanning Droplet Cell. Bipolar plate coatings screened simultaneously for corrosion resistance and contact resistance under acidic and alkaline operating conditions.

Co · Fe · Ni · Mn · Ir · Ru · Mo · Cr · Ti · Al · N
Hard Coatings
Nitride Hard Coatings

Quaternary and quinary nitride systems for cutting tools and wear-resistant components screened for hardness, elastic modulus, and phase stability. The composition space for high-entropy nitrides exceeds what sequential testing can cover. The platform maps it in one campaign.

Cr · Al · Ti · Si · Nb · W · V · N
Microelectronics
BEOL Barriers & Spin Hall Materials

Transition-metal nitride diffusion barriers applicable to systematic screening for amorphous phase stability and resistivity at sub-5nm thickness. Multi-element spin Hall layer composition spaces are directly mappable using MOKE and 4-point probe, relevant to SOT-MRAM integration.

Ta · Ti · Co · W · Ru · Pt · Ir · Al · N
Piezoelectrics & RF
Piezoelectric Nitride Films

Al-Sc-N and higher-order nitride systems are well suited to composition-spread screening for phase stability and crystal structure across the full composition gradient using automated XRD. Relevant to BAW filter, FBAR, and MEMS device development where Sc content and alloying element choice determine device performance.

Al · Sc · N · Mg · Y · B · Cr
Magnetics
Rare-Earth-Free Permanent Magnets & Magnetic Films

Multi-element alloy spaces applicable to systematic mapping of coercivity, saturation magnetization, and phase formation using automated MOKE and XRD. Covers both RE-free permanent magnet candidates and functional magnetic thin films for sensors and memory.

Mn · Al · Fe · Co · Ni · Ga · B · W · Ta
Glass & Optical
Functional Optical Coatings

Solar control, low-emissivity, and color-functional coatings screened for transmittance, reflectance, and emissivity across the composition space using UV-VIS spectroscopy. Transparent conductive oxide alternatives to ITO mapped simultaneously for sheet resistance and optical performance.

Ag · Zn · Sn · In · Ti · Al · Si · O · N
Energy & High Temperature
Battery Interfaces & Thermal Barrier Coatings

Solid-state battery interface layers screened for ionic conductivity and electrochemical stability window. High-temperature oxide systems screened for phase stability, thermal conductivity, and oxidation resistance, relevant to aerospace thermal barrier and nuclear fuel cladding applications.

Li · Si · Ge · Zr · Y · Ce · Hf · Al · O
Quantum & Advanced Materials
Superconducting & Emergent Materials

Multi-element composition spaces screened for superconducting transition temperature, novel phase formation, and emergent electronic properties using XRD and resistivity mapping. The platform is well suited to any system where the target property depends non-linearly on composition.

Nb · Ti · V · Mo · Zr · Al · N
Team

The people behind
the platform.

Dr.-Ing. Lars Banko
Chief Technology Officer

Lead scientist and platform architect. His doctoral research focused on high-throughput thin-film deposition and automated characterization methods for materials discovery, with particular emphasis on combinatorial electrochemistry using the Scanning Droplet Cell. Corresponding or contributing author on the core publication series. He built the physical and computational infrastructure that xemX operates.

M.Sc. Sven Maihöfer
Chief Operating Officer

Leads commercial and partnership development. Manages engagement with industrial partners across electrochemistry, hard coatings, semiconductor materials, and energy systems, translating application requirements into research campaigns and structuring xemX's relationships with customers and funding programs.


Scientific Advisory Board
Prof. Dr.-Ing. Alfred Ludwig
Chair of Materials Discovery and Interfaces · ZGH · Ruhr-Universität Bochum

One of Europe's foremost researchers in combinatorial and high-throughput materials science. Scientific Director of the ZGH (Center for Interface-Dominated High-Performance Materials). Pioneer of combinatorial thin-film methods for discovery of shape memory alloys, superconductors, catalysts, and functional coatings since the early 2000s. The methodological foundation of the xemX platform originated in his group. 14,000+ citations.

Prof. Dr. Wolfgang Schuhmann
Chair of Analytical Chemistry · Center for Electrochemical Sciences · Ruhr-Universität Bochum

World authority in electroanalytical chemistry and scanning electrochemical methods. His group developed and validated the Scanning Droplet Cell methodology that provides xemX's electrochemical characterization capability. 600+ publications. 2018 Alessandro Volta Medal, Electrochemical Society.

How It Works

From problem to
composition-property map.

01
Problem definition

You define the target properties, the element set, and any constraints. We establish which characterization methods are relevant and what a useful output dataset looks like for your application.

02
Campaign design

We determine the deposition geometry and cathode configuration to cover the relevant slice of composition space. For higher-order systems, permutation strategies extend coverage across multiple libraries.

03
Deposition and characterization

A 100mm wafer is co-sputtered with up to 8 elements simultaneously, producing a continuous composition gradient across 342 measurement points. Automated characterization runs across every point: XRD, electrochemistry, nanoindentation, resistivity, and others as required.

04
Data delivery and follow-on

You receive a structured composition-property dataset identifying where in the element space the target properties exist. If a promising composition is identified, we can produce homogeneous coatings of that composition for further validation on your substrates.

Application Note

Co-Fe-Ni-Mn high-entropy alloy
electrocatalysts for alkaline water electrolysis.

SystemCo-Fe-Ni-Mn quaternary HEA
ApplicationAlkaline water electrolysis OER
Key propertyElectrocatalytic activity and stability
CharacterizationScanning Droplet Cell · XRD · EDX
PublicationBanko et al., Advanced Energy Materials 2022

High-entropy alloy electrocatalysts offer a vast composition space for tuning catalytic properties, but the combinatorial explosion of possible compositions makes sequential testing impractical. A data-guided combinatorial synthesis strategy was used to map activity and stability across the full quaternary Co-Fe-Ni-Mn composition space in a single campaign.

342 unique compositions were deposited and characterized by automated Scanning Droplet Cell electrochemistry and XRD phase mapping. The resulting dataset was used alongside computational modeling to identify composition-activity-stability trends that would be inaccessible to conventional one-at-a-time experimentation.

The campaign identified multi-metal compositions with activity competitive with benchmark catalysts at significantly reduced noble metal content, directly addressing the cost and scarcity constraints on PEM electrolyzer scale-up.

Publications

Selected papers from
the platform's scientific record.

Seven papers representing the full range of what the platform does: composition screening, AI-guided exploration, autonomous characterization, phase mapping, hard coatings, high-entropy nitrides, and electrochemical discovery.

2025
Accelerating Combinatorial Electrocatalyst Discovery with Bayesian Optimization: A Case Study in the Quaternary System Ni-Pd-Pt-Ru for the Oxygen Evolution Reaction
Thelen, Zehl, Zerdoumi, Bürgel, Banko, Schuhmann, Ludwig · Advanced Science
Found the global activity optimum after covering less than 20% of the composition space. Demonstrates closed-loop AI-guided composition exploration on the platform.
doi:10.1002/advs.202507302 ↗
2025
Computationally Accelerated Experimental Materials Characterization: Drawing Inspiration from High-Throughput Simulation Workflows
Stricker, Banko, Sarazin, Siemer, Janssen, Zhang, Neugebauer, Ludwig · npj Computational Materials
Active-learning characterization loop that fuses computational priors with live experimental measurements, enabling autonomous decision-making on which composition points to measure next.
doi:10.1038/s41524-025-01919-5 ↗
2023
High-Throughput Exploration of Structural and Electrochemical Properties of the High-Entropy Nitride System (Ti-Co-Mo-Ta-W)N
Ludwig group · Advanced Engineering Materials
Five-element high-entropy nitride libraries by reactive co-sputtering with automated XRD, nanoindentation, resistivity, and SDC electrochemistry at every composition point. Direct demonstration of the platform applied to HEN coating systems.
doi:10.1002/adem.202300550 ↗
2023
A Flexible Theory for Catalysis: Learning Alkaline Oxygen Reduction on Complex Solid Solutions within the Ag-Pd-Pt-Ru Composition Space
Clausen, Krysiak, Banko, Pedersen, Schuhmann, Ludwig, Rossmeisl · Angewandte Chemie
SDC electrochemical screening of 1,582 alloy compositions combined with ML-derived adsorption energy descriptors. Demonstrates the platform's throughput enabling theory-quality datasets.
doi:10.1002/anie.202307187 ↗
2022
Unravelling Composition-Activity-Stability Trends in High Entropy Alloy Electrocatalysts by Using a Data-Guided Combinatorial Synthesis Strategy and Computational Modeling
Banko, Krysiak, Pedersen, Xiao, Savan, Löffler, Baha, Rossmeisl, Schuhmann, Ludwig · Advanced Energy Materials
Core result paper. Introduces the deposition source permutation strategy for extending composition space coverage in quinary systems.
doi:10.1002/aenm.202103312 ↗
2021
Deep Learning for Visualization and Novelty Detection in Large X-ray Diffraction Datasets
Banko, Maffettone, Olds, Naujoks, Ludwig · npj Computational Materials
Automated XRD phase analysis at scale using deep learning. Describes the AI layer that processes the 342-point XRD dataset from each campaign.
doi:10.1038/s41524-021-00575-9 ↗
2019
Effects of the Ion-to-Growth Flux Ratio on the Constitution and Mechanical Properties of Cr₁₋ₓAlₓN Thin Films: A Combinatorial Study Including Plasma Diagnostics
Banko et al. · ACS Combinatorial Science
Reactive DC magnetron sputtering of nitride hard coatings with automated XRD phase mapping and plasma diagnostics. Demonstrates the platform's capability for nitride systems.
doi:10.1021/acscombsci.9b00123 ↗