Abstract :

Two-Dimensional (2D) magnetic crystals are for all intents and purposes almost totally new entities. The physics of these objects is original, with open questions related to the qualitative changes in magnetic behaviour observed while changing the number of layers, the anisotropy requirements for the magnetic order to overcome thermal fluctuations, the conditions required to maximize the transition temperature, etc. This presentation is focused on materials that can act as bulk precursors for 2D magnetic crystals : magnetically ordered rare-earth (RE) MAX phases, and their derivatives. MAX phases are a family of nanolamellar compounds offering a wide range of exciting properties. When RE are added to these materials, the localised 4f orbitals coupled with their lamellar character gives rise to rich physics : metamagnetism, Kondo physics, complex magnetic structures, etc. These properties can then be readily tuned by changing the RE element. The first goal of the present work was to grow high quality and sizable single crystals (SC) of these magnetic compounds. Characterisation measurements were performed on these SCs, allowing us to gain insight into their physical properties. Synchrotron absorption was extensively used, as it allowed us to probe the magnetism and the effect of the environment on each of the chemical elements of the compounds, independently. Then, the various measurements were combined and analysed together in order to decipher and whenever possible quantify these properties.

Contact : annie.ducher@grenoble-inp.fr