Séminaire DMONS – DCMI – Axe 5 présenté par : Abhishake MONDAL

Abhishake MONDAL (Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore)

Abstract : 

The pursuit of smart multifunctional materials with stimuli-responsive magnetic and optical response has drawn escalating interest in both fundamental science and potential applications to switches, sensors, and intelligent devices.1 One of the appealing feature of such materials is the tunability of their physical property via chemistry, where the linking structure and physical properties can be modulated in practically infinite ways, which gives them an edge over the solid-state magnetic materials (Figure 1, a).2 The field of molecular bistable systems is rapidly budding towards utilizing these molecule-based magnetic materials in physics-driven and nanotechnology-driven fields (Figure 1, b).

Figure 1: a) Stimuli-responsive molecular bistable systems and b) Application areas where these systems are actively studied for developing devices

Here, I will briefly cover the exciting field of Molecular Magnetism and will specifically focus on three most important aspects of Molecular Magnetism being pursued in my laboratory i) Spin Crossover (SCO) materials3 ii) Metal-to-Metal Electron Transfer Systems (MMET)4 and iii) Single Molecule Magnets (SMM).5 Lastly, I shall discuss the application of these bistable systems in developing ring-resonator devices for Photonics Application, molecular break junctions and microelectromechanical systems.

Acknowledgments: I thank the Indian Institute of Science (IISc), Bangalore, India, and the Ministry of Human Resource Development (MHRD), Ministry of Education (MoE), Government of India, IISc-Start-up Research Grant, the Department of Science and Technology, Mission on Nano Science and Technology (Nano Mission), Scheme for Transformational and Advanced Research in Sciences (STARS, MHRD), Council of Scientific and Industrial Research (CSIR) for the research fundings.

References:

1. Kamilya, S.; Dey, B.; Kaushik, K.; Shukla, S.; Mehta, S.; Mondal, A. Chem. Mater. 2024, 36, 4889, Kaushik, K.; Mehta, S.; Das, M.; Ghosh, S.; Kamilya, S.; Mondal, A., Chem. Commun., 2023, 59, 13107, Coronado, E., Nat. Rev. Mater. 2020, 5, 87. 2. Minguez Espallargas, G.; Coronado, E., Chem. Soc. Rev. 2018, 47, 533. 3. Ghosh, S.; Kamilya, S.; Pramanik, T.; Rouzieres, M.; Herchel, R.; Mehta, S.; Mondal, A., Inorg. Chem. 2020, 59, 13009, Ghosh, S.; Ghosh, S.; Kamilya, S.; Mandal, S.; Mehta, S.; Mondal, A., Inorg. Chem. 2022, 61, 17080, Bagchi, S.; Kamilya, S.; Mehta, S.; Mandal, S.; Bandyopadhyay, A.; Narayan, A.; Ghosh, S.; Mondal, A., Dalton Trans., 2023, 52, 11335, Ghosh, S.; Bagchi, S.; Kamilya, S.; Mehta, S.; Sarkar, D.; Herchel R.; Mondal, A., Dalton Trans., 2022, 51, 7681. 4. Kamilya, S.; Ghosh, S.; Li, Y.; Dechambenoit, P.; Rouzières, M.; Lescouëzec, R.; Mehta, S.; Mondal, A., Inorg. Chem., 2020, 59, 11879, Kamilya, S.; Ghosh, S.; Mehta, S.; Mondal, A., J. Phys. Chem. A 2021, 125, 4775. 5. Hossain, S. M.; Kamilya, S.; Ghosh, S.; Herchel, R.; Kiskin, M. A.; Mehta, S.; Mondal, A., Cryst. Growth Des. 2023, 23, 1656.

Soutenance de thèse : Satakshi Pandey

Satakshi Pandey (IPCMS / DMONS)

La soutenance aura lieu Vendredi 18 octobre à 9h30 à l’auditorium de l’IPCMS

Ce travail a été réalisé sous la direction du Dr Jean François Dayen et du Dr David Halley (DMONS).

Mini-workshop Franco-Indien sur les matériaux et dispositifs ferroïques bi-dimensionnels

Ce workshop est organisé avec le soutien du CEFIPRA, des Ministères des affaires étrangères français et indiens, et de l’ITI QMAT.

Une vingtaine de présentations orales sont programmées.
Les orateurs sélectionnés proviennent du monde académique et du monde industriel.
Nous échangerons sur des aspects touchant aux propriétés fondamentales de ces matériaux et à leurs applications, notamment dans le domaine des mémoires et des technologies de l’information.

Plus d’information sur le flyer ci-joint et sur le site du workshop :
https://sites.google.com/view/if-wo2dfm2024/home

Cette journée est ouverte à tous, et gratuite.
Pour des raisons d’organisation, Merci de prévenir avant le 26 juin 12h00 de votre participation par email à dayen@unistra.fr.

Workshop SWING

The goal of this workshop is to gather the French community working in the broad field of magnonics (i.e. physics and technologies of spin waves). This workshop will also serve as a scientific kick-off of the project SWING, whose focus is on applied magnonics, and which is part of the recently funded program PEPR Spin.

Please find extra information (schedule, registration submission) at  https://swing-workshop1.sciencesconf.org/

Séminaire DMONS présenté par Kshirsagar Aseem RAJAN

  1. Light tunable gas adsorption in functionalized metal-organic frameworks: insights from ab initio methods Metal-organic frameworks (MOFs) functionalized with azobenzene, a photo-isomerizing molecule, are capable of light stimulated capture and release of CO2. Using ab initio density functional theory (DFT) based atomistic modelling, the microscopic mechanism behind the light tunable gas uptake in azobenzene functionalized MOF-5 is revealed to be the blocking and unblocking of the metal-node, by distinct geometric configurations of azobenzene. A practical environment-consistent Bethe-Salpeter equation (BSE) approach is used for an accurate description of the photo-excitations of the photo switches to propose strategies for achieving high yields of photo switching. Our study also shows that electronic excitations in the prototype MOF-5 give rise to strongly bound states of electron-hole pair, analogous to organic insulators.
  2. Modulation of magnetization in BiFeO3 using circularly polarized light Dynamic and efficient control of the characteristic spin texture of multiferroic BiFeO3 is attractive for emerging quantum devices. Crystal-field d → d excitations localized on Fe atomic sites in BiFeO3 induce a complex interplay among the spin, charge and lattice degrees of freedom, making them relevant for manipulation of the spin texture. Ab initio methods based on the GW approximation and the BSE are used to characterize localized spin-flip excitations within Fe-3d shell. These excitations are strongly bound and appear deep within the electronic gap. Their spin-content and strong localization are protected by the antiferromagnetic ordering. The underlying crystal symmetry gives rise to chiral spin-flip exciton states localized on distinct Fe centers. These chiral excitons couple selectively to light of a particular circular polarization and are confined to a particular Fe magnetic sub-lattice. As a consequence, net spin- magnetization can be achieved using circularly polarized light coupling with exciton of desired chirality, thereby modulating the antiferromagnetic texture and giving rise to transient ferrimagnetism.
  3. Future directions: Understanding charge-lattice-spin coupling using ab initio methods
    In transition-metal oxides, localized excitons can give rise to a complex interplay of spin-charge-lattice degrees of freedom. I intend to motivate and sketch an investigation of the coupling of these excitons with lattice motion and its relevance for optomechanical control.

Pour tout contact : Mébarek ALOUANI : mebarek.alouani@ipcms.unistra.fr