Open PhD positions

7 PhD positions at the Centre for Nanotechnology and Advanced Materials, Bratislava, Slovakia

 

Job Information

 

Organisation/Company: Comenius University Bratislava, Faculty of Mathematics, Physics and Informatics

Department: Centre for Nanotechnology and Advanced Materials

Research Field: Solid state physics

Researcher Profile: First Stage Researcher (R1)

Positions: PhD Positions

Country: Slovakia

Application Deadline: 15 March 2025 – 23:59 (Europe/Bratislava)

Type of Contract: Temporary

Job Status: Full-time

Hours Per Week: 37.5

Offer Starting Date: 1 Sep 2025

Is the job funded through the EU Research Framework Programme?: Not funded by a EU programme

Is the Job related to staff position within a Research Infrastructure?: No

 

Offer Description

 

We are looking for seven PhD. candidates for a 4-year study program in experimental solid-state physics at the Centre for Nanotechnology and Advanced Materials, Faculty of Mathematics, Physics and Informatics, Comenius University Bratislava, Slovakia. If you like working in a team and have solid background in solid-state physics or related field of study with the emphasis to one of the topics below, one of these positions might be for you.

 

1) Advancing Dissipation-Free Electronic Devices through Probing and Engineering Superconductor/Ferromagnet Interface Structures

Supervisor: Assoc. prof. Maroš Gregor

Contact: maros.gregor@fmph.uniba.sk

Abstract: The thesis explores the potential use of three-dimensional heterogeneous technology by creating new 3D heterostructures with high integration density. The research focuses on optimizing S/F interfaces, exploring proximity effects, and characterizing new materials to improve the efficiency and functionality of hybrid devices. Additionally, the study proposes the fabrication of multilayer structures with alternating superconducting (S), normal (N), and ferromagnetic (F) layers to explore their unique topological properties, aiming to stabilize exotic quantum states. The interdisciplinary nature of the project holds promise for the development of novel devices with improved reliability, efficiency, and performance for future quantum technologies. The primary objective of this work is to advance the understanding and design of S/F interface structures to enhance the performance of hybrid devices, where ferromagnets closely interact with superconducting elements, thereby enabling novel functionalities for next-generation electronic systems.

 

2) Concept of diboride multilayers with improved fracture toughness

Supervisor: Assoc. prof. Marián Mikula

Contact: marian.mikula@fmph.uniba.sk

Abstract: The dissertation focuses on enhancing the fracture toughness of inherently hard and brittle diboride coatings prepared via physical vapor deposition. Transition metal diboride (TMB₂) coatings (TM = Y, Ti, Zr, Nb, V, Ta, W, Mo) form a nanocomposite structure with TMB₂ nanofilaments surrounded by an amorphous boron-tissue phase, achieving extreme hardness (H > 40 GPa). However, their low fracture toughness makes them prone to microcracks, facilitating oxidation at high temperatures. A promising solution is the use of multilayer coatings (e.g., TiB₂-TaB₂), where nanoscale layers improve toughness by deflecting crack propagation due to differences in lattice parameters and shear moduli. These coatings will be synthesized using advanced physical vapor deposition techniques, particularly HiPIMS magnetron sputtering. Mechanical properties will be evaluated via nanoindentation, while micromechanical cantilever testing (prepared by FIB) will assess fracture toughness. Additional analyses – including SEM, EDS, WDS, XPS, XRD, and TEM – will examine thermal stability, and phase transformations. Furthermore, density functional theory (DFT) calculations will support the experimental work, providing deeper insights into the mechanical behavior of diboride systems.

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[1] Fiantok, T., Koutná, N., Sangiovanni, D.G., Mikula, M., Ceramic transition metal diboride superlattices with improved ductility and fracture toughness screened by ab initio calculations Scientific Reports, 2023, 13(1), 12835. https://doi.org/10.1038/s41598-023-39997-4

[2] Vidiš, M.,M., Fiantok T., Gocník M., Švec P., Jr., Nagy Š., Truchlý M., Izai V., Roch T., Satrapinskyy L., Šroba V., Meindlhumer M., Grančič B., Kúš P., Keckes J., Mikula M., Hardness and fracture toughness enhancement in transition metal diboride multilayer films with structural variations, (2024) Materialia, 34, art. no. 102070, DOI: 10.1016/j.mtla.2024.102070

 

3) Design of oxidation-resistant TMB₂ coatings through defect engineering

Supervisor: Assoc. Prof. Marián Mikula

Contact: marian.mikula@fmph.uniba.sk

Abstract: The dissertation is focused on improving the oxidation resistance of selected transition metal diboride (TMB₂) coatings prepared by physical vapor deposition techniques. Although TMB₂ coatings exhibit outstanding hardness and thermal stability, their application at elevated temperatures is limited by insufficient resistance to oxidation, which is strongly influenced by the defect structure of the coating. The central idea of this work is to tune the oxidation behavior of selected diborides through defect engineering, with particular emphasis on planar defects introduced during growth. Controlled modification of the defect density and arrangement is expected to influence oxygen transport, oxide scale formation, and the adhesion and stability of the formed oxides. Additional tuning will be achieved by alloying with selected elements and by tailoring the nanostructure of the coatings. The coatings will be deposited using advanced physical vapor deposition techniques, with a focus on HiPIMS magnetron sputtering, enabling precise control of ion bombardment and defect formation. Oxidation behavior will be investigated under high-temperature conditions, while structural and chemical changes will be analyzed using electron microscopy, X-ray–based techniques, and spectroscopy methods. The integrity of oxidized coatings and the role of defects in oxidation-induced degradation will be systematically evaluated. Experimental investigations will be supported by density functional theory (DFT) calculations to provide atomistic insight into defect stability and oxygen incorporation mechanisms in defect-engineered TMB₂ systems. The results will contribute to the development of design principles for oxidation-resistant diboride coatings based on controlled defect structures.

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[1] Mikula, M. et al., Yttrium-induced structural evolution and oxidation resistance in TiB2+Δ coatings deposited by conventional magnetron sputtering and HiPIMS Surface & Coatings Technology 515 (2025) 132674

 

4) Fabrication and structural analysis of functional coatings

Supervisor:  Assoc. prof. Tomáš Roch

Contact: tomas.roch@fmph.uniba.sk

Abstract: The content of the dissertation will be the study of structural and transport properties of selected types of hard coatings based on borides and nitrides of transition metals in accordance with the plan of the workgroup and within the framework of ongoing projects. It will also be possible to include mixed transparent conductive oxides in the work, which are very interesting from an application point of view. The doctoral student will participate in the preparation of samples by various methods of physical vapor deposition. He/she will investigate the correlations of structural properties and chemical composition, e.g. with transport, mechanical and optical properties and their possibility of modification by changing the parameters of the preparation of thin layers. Complementary information on the morphology of surfaces to the structural properties from X-ray scattering analyses will be provided by scanning electron microscopy, transmission electron microscopy, and various modes of scanning probe microscopy. The work will also include a detailed study of the temperature stability of the physical properties of the examined coatings and their oxidation resistance. The main focus will be on structural analysis of coatings. Depending on the degree of crystallinity, advanced methods of X-ray structural analysis will be used to investigate the crystalline phase composition of the layers, the level of preferential orientation, lattice misfit to the substrate, residual stresses and the degree of relaxation, and the presence of various defects. In the case of amorphous coatings with short-range order, methods based on pair distribution function analysis will be applied. To prepare scientific outputs, this research will be supplemented by other complementary analytical and spectroscopic methods. A range of methods for investigation of transport and optical properties is available within workgroup. The doctoral student will attend to his/her study duties chronologically according to his/her individual study plan.

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[1] review articles related to selected material group

[2] M.Birkholz: “Thin film analysis by X-ray scattering”, Wiley-VCH Verlag GmbH, Weinheim, 2006

 

5) Structure and properties of transition metal monoborides

Supervisor: Dr. Branislav Grančič

Contact: branislav.grancic@fmph.uniba.sk

Abstract: Transition metal borides (TMBy) represent a structurally rich group of materials. Owing to the combination of ionic, covalent, and metallic bonding, they exhibit high hardness, good electrical conductivity, and excellent thermal resistance. For boron-to-metal ratios between 1 and 2, planar defects such as antiphase and twin boundaries frequently occur in these materials. With appropriate defect engineering, these defects can contribute to improved material properties [1, 2]. Compared to traditional diborides, such films may exhibit higher oxidation resistance and greater fracture toughness, making them promising as hard yet electrically conductive materials for applications in demanding operating conditions. This study will focus on the synthesis of crystalline TMBy thin films with a B/TM ratio close to 1 using various physical vapor deposition (PVD) techniques, including direct current magnetron sputtering (DCMS), high-power impulse magnetron sputtering (HiPIMS), pulsed laser deposition (PLD), and high target utilization sputtering (HiTUS). The research will aim to understand the influence of deposition conditions on the formation of planar defects and their impact on the mechanical and electrical properties of the films. Characterization will be carried out using EDS, WDS, XPS, XRD, TEM, nanoindentation, and electrical measurements performed with a PPMS system.

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[1] K. Viskupová, B. Grančič, T. Fiantok, P. Švec, R. Vrablec, T. Roch, M. Truchlý, V Šroba, V. Izaii, Z. Hájovská, M. Mikula. Thermally induced formation of nanotwins in magnetron sputtered TaB1+d films, Acta Materialia 305 (2026) 121873, https://doi.org/10.1016/j.actamat.2025.121873

[2] K. Viskupová, T. Fiantok, B. Grančič, P. Švec, T. Roch, M. Truchlý, V. Šroba, L. Satrapinskyy, P. Kúš, M. Mikula, Heterostructural decomposition in V1-xWxB2-Δ films induced by B deficiency, Materialia (2025) 102351 https://doi.org/10.1016/j.mtla.2025.102351

 

6) Structural design of transition metal-based NEG coatings using modern pulse sputtering techniques

Supervisor: Dr. Vitalii Izai

Contact: vitalii.izai@fmph.uniba.sk

Note: From the second year, this doctoral thesis will be carried out at the faculty’s detached workplace in Turany, Slovakia.

Abstract: NEG coatings are non-evaporable getter coatings usually based on transition metal alloys applied on the surfaces of UHV vacuum parts exposed to vacuum. These coatings provide distributed pumping in UHV range in narrow areas of synchrotrons, particle accelerators, etc. where conventional pumping using turbomolecular or ion pumps is geometrically limited by the low internal dimensions and reduced pumping cross-section. The NEG coating is designed to be activated during conventional bakeout of UHV equipment at 180-200 °C and is characterized by sorption rate, minimal activation temperature and time, photo-stimulated and electron-stimulated desorption of coated surfaces. The most well-known NEG coating up to date is based on Zr-Ti-V alloy. Usually, this coating is applied on the internal surfaces of UHV parts by cathodic DC sputtering from twisted wires of pure Zr, Ti, and V metals in Kr gas. External axial magnetic field generated by outer solenoids is often applied to increase the ion current density and sputtering rate. However, the sputtering power needs to be maintained at relatively low levels due to the twisted wire cathode overheating which makes the UHV design of coating setup mandatory. From the other hand, a demand of coating the outer surfaces of the UHV parts with NEG coatings is observed. These parts need to be coated in conventional industrial batch coaters using planar magnetron sputtering sources. The UHV design of deposition chamber is almost impossible in this case. In addition, operating conditions in industrial magnetron sputtering are in different ranges compared to cathodic DC sputtering. However, modern magnetron-based PVD coaters, equipped with HiPIMS power supplies, provide the experimenter with additional actuators for changing the structure and properties of the deposited NEG coatings. While there are numerous publications dedicated to the deposition process and properties of NEG coatings deposited on internal surfaces by conventional procedure, there is a lack of information regarding deposition of NEG coatings using planar magnetron sputtering including HiPIMS. The aim of this work is to study the peculiarities of the deposition process, and the resulting properties of Zr-Ti-V based NEG coatings using conventional planar DC magnetron sputtering technique, the influence of HiPIMS sputtering parameters on the structure and properties of Zr-Ti-V based NEG coatings, to disclose and understand the interrelations between the deposition parameters and resulting properties, and to compare these coatings with Zr-Ti-V based NEG coatings deposited on internal surfaces of UHV parts in conventional way.

 

7) Friction, Wear, and Oxidation Behavior of Transition Metal Diboride Thin Films

Supervisor: Dr. Martin Truchlý

Contact: martin.truchly@fmph.uniba.sk

Note: From the second year, this doctoral thesis will be carried out at the faculty’s detached workplace in Turany, Slovakia.

Abstract: This dissertation systematically investigates the tribological properties of selected transition metal diborides (TMB₂) in the form of thin films deposited by physical vapor deposition (PVD). Despite their exceptional mechanical properties, these materials have yet to find widespread application as tribofunctional or low-friction coatings. Fundamental tribological characteristics of binary and ternary diborides remain largely unexplored, including coefficients of friction (COF) across diverse tribosystems (TMB₂-steel, TMB₂-Al or Al-based alloys, TMB₂-ceramics such as Al₂O₃ or Si₃N₄), wear mechanisms, specific wear rates, and high-temperature behavior. The study also examines their oxidation resistance, since tribological contacts often generate significant localized heating (flash temperatures) that can influence coating performance. Tribo-oxidation products will be analyzed, as many may themselves represent promising tribomaterials. Additionally, sliding properties at elevated temperatures up to 1000 °C will be studied. Promising materials hold potential for applications in the aerospace industry, machining of hard-to-cut alloys, and other extreme environments. Thin films will be prepared using various PVD techniques, ranging from conventional DC magnetron sputtering to high-power impulse magnetron sputtering (HiPIMS) and innovative high-target utilization sputtering (HiTUS). Their properties will be characterized via scanning electron microscopy (SEM), transmission electron microscopy (TEM), nanoindentation, scratch testing, energy-dispersive X-ray spectroscopy (EDS), wavelength-dispersive X-ray spectroscopy (WDS), X-ray photoelectron spectroscopy (XPS), and other methods. The results will contribute to the development of design principles for advanced tribological diboride coatings.

 

 

Requirements:

  • Master’s degree in solid state physics or related study program.
  • Strong background in solid state physics with the focus on areas relevant to the chosen PhD topic (e.g. superconductivity, structural and mechanical properties of solids, etc.).
  • Analytical thinking, good communication skills, ability to work in a team.
  • At least B2 level in written and spoken English.

 

 

Additional highly appreciated (non-mandatory) experiences, depending on the topic, are for example:

  • Publication of articles in international peer-reviewed journals, presentations at conferences.
  • Deposition of thin films by PVD methods.
  • Electrical characterization of materials and devices.
  • Analytical methods such as XRD, XPS, SEM, EDX, AFM, etc.
  • Characterization of mechanical properties of coatings by nanoindentation, scratch tests, microtribometry, etc.
  • Programming (e.g. Python, Matlab, LabVIEW, …).
  • Background in inorganic chemistry.

 

 

What we offer:

  • Meaningful work within a friendly and experienced research team.
  • Well-equipped laboratories.
  • Accommodation: On-campus accommodation in a dormitory (approx. 100 – 200 € per month depending on the room quality), or assistance with finding another type of accommodation.
  • Scholarship of 1 097,50 € / mo. netto (1 278 € after successful completion of the qualification exam) + occasional bonuses from research projects.

 

Important dates:

15 March 2025 – Deadline for submitting the pre-application

21 March 2025 – Results of the pre-selection (via email)

23 March – 1 April 2025 – Online interview(s)

30 April 2025 – Deadline for submitting the final application to the faculty (along with payment of the application fee of 15 – 33 €)

June 2025 (will be specified later) – Admission exam (oral examination by the admission committee, online possible)

Approx. end of June 2025 – Results of the admission exam.

 

Application process:

By submitting the pre-application you enter the pre-selection process, after which the PhD supervisor will support one PhD candidate for submitting the final application to the faculty. Pre-selected candidate(s) will be invited for an online interview and will be instructed further.

The pre-applications should be submitted until 15 March 2025 via email to the respective supervisor and should include:

 

– Title of the PhD topic you are applying for.

– CV (max. 3 pages).

– Motivation letter (max. 1 page).

– A list of subjects taken during the master’s study including grades/percentages.

– The title and a short description of your master’s thesis (can be included in the CV or in the motivation letter).

– At least two references.

– In case you have a clear idea of your PhD research project which is similar or at least related to the proposed PhD topic, you are welcome to submit also your own research proposal (max. 2 pages). This is not mandatory.

 

Incomplete pre-applications will not be considered.

 

Where to apply

To apply, please send your pre-application via email directly to the supervisor of the respective topic.

 

Requirements

Research Field: Solid state physics or related

Education Level: Master’s degree or equivalent

Languages: ENGLISH

Level: Excellent / B2 or higher

 

 

Additional Information

Additional information regarding the study program, submission of the final application and other details such as health insurance can be found at: https://fmph.uniba.sk/en/admissions/doctoral-degree-programs/

 

Work Location(s)

Number of offers available: 7

Company/Institute: Comenius University Bratislava, Faculty of Mathematics, Physics and Informatics, Centre for Nanotechnology and Advanced Materials

Country: Slovakia

City: Bratislava

Postal Code: 84248

Street: Mlynská dolina F1

 

For topics No. 6 and 7, the work location from the 2nd year of study will be:

Country: Slovakia

City: Turany

Postal Code: 035 83

Street: Sadová 1148