RS Fellow - EPSRC grant (2014): Exploring high temperature superconductivity in novel layered materials.

Lead Research Organisation: University of Manchester
Department Name: Physics and Astronomy

Abstract

Two dimensional (2D) material research has emerged with the isolation of the first 2D material named graphene, in 2004. Graphene is a single atom thick sheet of carbon atoms arranged in a honey comb lattice. It is considered as a potential material for different wide-ranging applications because of its exceptional properties. It is the thinnest and strongest material known and it is transparent and conducts electricity even better than copper. It is completely impermeable to gases and liquids and extremely flexible. For the last few years, the scientific community was heavily looking into the fabrication of other one atom thick planes from layered materials, including insulators, semiconductors and superconductors. The availability of these new 2D materials with diverse properties opens up many possible opportunities in materials design and engineering. For example, by stacking different 2D atomic sheets on top of each other in a desired sequence will result in the formation of new three dimensional materials with novel properties. Recently, the Manchester group demonstrated this concept by combining graphene with semiconducting molybdenum disulfide to fabricate a new type of vertical transistors.

Motivated by this initial result, my particular interest is to fabricate novel layered materials with structures similar to that of high temperature layered superconductors. Superconductivity is a phenomenon of zero electrical resistance and complete expulsion of magnetic field. In high temperature superconductors (HTS), superconductivity arises from the alternating layers of conducting and insulating layers of atoms, which form the HTS crystal. With the availability of different 2D crystals, I envisage to design materials with a similar structure by stacking different 2D crystals on top of each other. The search for HTS is an ambitious project, but if I am successful in making HTS based on these novel materials, this could spark massive interest.

Planned Impact

Please refer to attached Royal Society application

Publications

10 25 50
 
Description We achieved superconductivity in calcium decorated graphene (Tc ˜ 6K) by intercalating collections of electronically decoupled graphene flakes in so-called graphene laminates with calcium. These highly doped graphene laminates are found to be less susceptible to environmental damage and allowed us to study superconducting properties of graphene. Our studies show that Tc of calcium decorated graphene is strongly dependent on the confinement of the Ca layer and the induced charge carrier concentration. In addition, our experiments show that Ca is the only dopant that induces superconductivity in graphene laminates above 1.8 K among all the alkali metals used in our experiments such as potassium, caesium and lithium. It is important to note that, in contrast to hyped theoretical predictions, no superconductivity could be detected above 1.8 K in Li decorated graphene samples.
Exploitation Route Our work demonstrates the prospect of studying the superconductivity in other 2D materials by using well separated laminates of 2D crystals and also shows the possibility of intercalating laminates containing a combination of different 2D materials.
Sectors Electronics

 
Description This work led to the first successful demonstration of superconductivity in doped graphene and the demonstration of alternating Superconducting and Charge Density Wave Monolayers within Bulk 6R-TaS2. We developed a novel yet simple method for producing vertical stacks of alternating superconductor and insulator layers of tantalum disulphide (TaS2). These findings could speed up the process of manufacturing such devices - so-called van der Waals heterostructures - with application in high-mobility transistors, photovoltaics and optoelectronics. This work has led to further research into the mechanism of interaction of atoms between graphene and its significance in energy applications by other research groups and also led to new research themes in Prof. Nair's group on bulk heterostructures. Our research also attracted interest from the media and was reported in several news outlets (e.g., nanotechweb, Frankfurter Allgemeine, Phys.org, nanowerk, etc.) and provided public awareness of the potential of superconducting materials and their applications.
First Year Of Impact 2016
Sector Education,Energy
Impact Types Societal

 
Description ERC starting grant
Amount € 1,400,000 (EUR)
Organisation European Research Council (ERC) 
Sector Public
Country Belgium
Start 05/2016 
End 04/2021
 
Description Collaboration with University of Antwerp 
Organisation University of Antwerp
Country Belgium 
Sector Academic/University 
PI Contribution We have provided research samples
Collaborator Contribution University of Antwerp performed modelling and electron microscopy studies
Impact https://pubs.acs.org/doi/10.1021/acs.nanolett.2c01851
Start Year 2018
 
Description Medai news 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact News article on our research and its intention was outreach. Received request for collaboration based on this activity.
Year(s) Of Engagement Activity 2022
URL https://phys.org/news/2022-08-significant-advance-2d-material-science.html