Abstract During recent years, new types of materials have been discovered with unique properties. One family of such materials is two-dimensional (2D) materials with unusual electronic, mechanical and optical properties, which led to their extensive study for diverse applications. Transition metal carbides, carbonitrides and nitrides (MXenes) are among the latest additions to the 2D world, which are derived from their layered precursors, MAX phases, layered early transition metal ternary carbides and nitrides, composed of M, an early transition metal, A, a group A element and X is C and/or N.
In this thesis, as its self-telling title indicated, we present our work on the synthesis, structural characterization and the electron transport in the MAX phases and 2D MXenes.
For MAX phases: using high temperature solution growth and slow cooling technique, several MAX phases single crystals have been successfully grown, including Cr2AlC, V2AlC, Ti3SiC2, etc. Structural characterization confirms the single crystalline character of the samples. Experimentally, a set of transport data was obtained from single crystals of V2AlC and Cr2AlC as a function of temperature and magnetic field. Theoretically, a general 2D nearly free electron model was proposed for describing the weak field magneto-transport properties of MAX phases.
For MXenes: large scale V2CTx (T stands for the surface terminations, hydroxyl, oxygen or fluorine)) MXene flakes were successfully synthesized. Mechanical delamination of multilayered V2CTx flakes into few layer flakes and transfer on Si/SiO2 substrate was also achieved. We then detailed the electrical device fabrication and proceeded with electrical measurements down to low temperature, with the aim to extract information on charge carrier behavior. First-hand transport data were obtained on V2CTx MXenes, which brings new understandings to this novel type of 2D material.
Jury de thèse : Dr. Jean-Christophe, CHARLIER - Université Catholique de Louvain, Belgique- Examiner Dr. Vincent, BAYOT - Université Catholique de Louvain, Belgique - Examiner Dr. Sylvain, DUBOIS - Université de Poitiers, France - Rapporteur Dr. Matthieu, VERSTRAETE - Université de Liège, Belgique - Rapporteur Prof. Thierry, OUISSE - Laboratoire LMGP - Grenoble INP, France - Thesis Director Prof. Benoît, HACKENS -Université Catholique de Louvain, Belgique - co-Thesis Co-director
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