Secondments & Interactions

Up to this point the main interactions have been with the other ESR in Southampton, Aleš Rapuc and Paola Torche. We discussed how to link the theoretical model developed by Paola to Aleš' measurements with AFM using the predictive power of my DFT calculations.

I also discussed with Antonio Cammarata from the CTU in Prague about how to describe accurately the layered structures of TMDs within DFT framework and how to compute the phonon spectra from first principles.

Recently, I am speaking with Kapil Bhorkar from FORTH-ICE\HT in Greece who is trying to synthetize the Ti:MoS₂ compound using CVD techniques.

We discussed the possibility for a secondment in Prague with Victor Claerbout and Paolo Nicolini during which I would learn how to use the LAMMPS software and carry out classical Molecular Dynamics simulations to study the frictional behaviour of graphene-MoS₂ heterostructures.

At this stage, the main interaction with the ESRs has been with Aleš Rapuc and Andrea Silva, which are both at Southampton University. We have discussed future articles we can write together, combining experiments done by Aleš, DFT simulations from Andrea to find the correct potential of interaction (this last would be an important input in the modelling at the mesoscopic level that I do). We have also talked with Victor and Paolo from Prague about the possibility of a joint project while we do our secondments next year in January-March.

Secondment in Prague, June 2018: Stick-slip measurement on WS₂ sample.

AFM training with dr. Kosta Simonovic (CVUT) and dr. Egor Ukraintsev (FZU) on NTEGRA AFM system. We have managed to set up a system to achieve a stick-slip measurement on WS₂ sample, which can be correlated with Prandtl-Tomlinson nano-friction model.

Raman spectroscopy training with dr. Kosta Simonovic (CVUT) and measurements of Raman spectra on CVD deposited MoS₂ and on amorphous sputtered Ti-MoS₂ samples.

• First secondment:
  Purpose: Course work at University of Coimbra
  November 11th 2017 to February 4th 2018
• Second secondment:
  Purpose: Sample testing of Mo-S-N on XRD, nano-indentation, Pin on disc equipment
  June 16th 2018 to july 7th 2018

Up to now, the only interaction that I have with other parts of the project is to meet them during SOLUTION meetings to discuss about our work. Also, from them I got informed about conferences and trainings related to our project.

Collaboration with Dr. S. N. Yannopoulos and PhD Student Kapil Bhorkar, FORTH/ICE-HT, Greece.

Samples that we received: films (layers) of Molybdenum, Tungsten, MoS₂, MoSe₂, WS₂ and WSe₂.

Experiment: we performed a biocompatibility assay using different type of films to study the biofilm formation of Staphylococcus aureus in the surface of the layers.

Secondment: FORTH/ICE-HT, Greece, in 2019 to perform metabolomics experiments.

Planning some coating depositions in Prague.

As for collaboration with other institutions in the consortium I have sent samples to Czech Technical University in Prague for Raman Spectroscopy.

• Secondments:University of Southampton (1 month), Comenius University in Bratislava (2 months)
• Sharing Mo-S-N samples with Aleš Rapuc for atomic force microscopy (AFM) and friction force microscopy (FFM) investigation
• Discussing the results and issues with Kaushik Hebbar Kannur (we both prepared and analysed Mo-S-N coatings using different methods) and other students in project, mainly; Ruben Herrero, Todor Vuchkov and Talha Bin Yaqub
• I have visited many times research departments of the project partners, namely:
  1. Department of Experimental Physics and Detached research facility in Turany (Comenius University in Bratislava, Faculty of Mathematics, Physics and Informatics) – preparation of the coatings using HiTUS, nanoindentation, tribo-testing in humid air, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), X-ray Photo-Electron Spectroscopy (XPS), Transmission Electron Microscopy (TEM)
  2. Faculty of Electrical Engineering (Czech Technical University in Prague) – Raman Spectroscopy, tribo-testing in vacuum
  3. Central European Institute of Technology in Brno (CEITEC) – SEM, Focused Ion Beam cutting (FIB), TEM

Technical Discussions about DFT study of MoS₂ coumpound with Andrea Silva; Theory to experiments discussions with Aleš Rapuc; Plan for 1st Secondment in preparation.

At this stage of my training the main interactions have been within the advanced materials group in Prague to which also ESR Florian Belviso belongs. For now, I have future collaborations planned mainly with the ESRs in Southampton, Andrea Silva and Paola Torche. This collaboration will be two-fold in which both Andrea and Paola will first visit Prague during which I will make them familiar with the MD simulations I perform. We have already discussed several ideas for possible topics on which we can focus. Thereafter, I will visit Andrea and Paola and they will make me familiar with the techniques they use. For this we are still thinking about possible topics to study.

The first planned secondment is in the University of Southampton. Learning about tribology equipment such as test rigs, SEM, Raman, AFM is one of the objectives. The other one is to analyse the samples already tested doing a coating characterization by SEM and Raman Spectroscopy.

We are in collaboration with IPN and IREIS developing different coatings to be tested in our disc-on-disc rig.

The first secondment of the ESR was expected to be realized by the end of 2018 at FORTH. Nevertheless, due to the resignation of Mrs. Leleviҫ, the secondment has been postponed. During the ESR’s work in the frame of the project, a visit at FORTH was made. During this visit various trials have been made to deposit Mo via CVD technique on top of composites provided by Artia. Owing to instrumental malfunction the work in FORTH was slowed down. During that visit at FORTH the ESR gained acquaintance with several techniques and scientific instruments provided by Dr. Spyros Yiannopoulos and his colleagues. Sharing the already made samples with the partners at University of Southampton was decided during 18M Meeting in July 2018, in ordered to be examined by AFM.

Due to the very limited time Mr. Mathioudakis has been working for the project, he hasn’t yet had the chance to interact in any way with other parts of the project.

• FORTH/ICE-HT visits Artia Nanoengineering
  We paid a visit to Artia Nanoengineering campus on the 22nd of February 2018. We had a detailed discussion about common topics of interest in the framework of SOLUTION ITN. We have been given a tour on the newly developed pilot line of electroplating process.
• CVD growth of MoS₂ on AFM tips for tribological studies
  Over the last 5 months we closely collaborate with the CVUT group in Prague (Paolo, Kosta, Ales, etc. …). We have designed and currently implement a novel experiment encompassing the growth of TMDChs on AFM tips. The Prague team will evaluate the frictional performance of the material at the nanoscale.
• Ti doping of MoS₂
  Over the last 3 months we have established collaboration with Antonio Cammarata to experimental investigate tribological properties of Ti-doped MoS₂ materials. Andrea Silva, an ESR at Southampton University is assisting this collaboration with theoretical predictions.
• Nanotoxicity at Burgos
  A systematic collaboration has been initiated since April 2018 with the Burgos team. We have supplied the team with several materials (MoS₂, MoSe₂, WS₂ and WSe₂) for toxicity studies by Brixhilda Domi (ESR at University of Burgos). They have sent us commercial MoS₂ and WS₂ powders for physicochemical characterization to supplement their toxicity studies.