In Honor of Nobel Laureate Prof. M Stanley Whittingham
| SOLID-STATE CHEMISTRY OF TRANSITION METAL FLUORIDES: FROM FLUOROPEROVSKITES TO INORGANIC NANOFLUORIDES - PHYSICAL-CHEMICAL PROPERTIES AND APPLICATIONS Alain Tressaud1; 1ICMCB-CNRS, UNIVERSITY BORDEAUX, Pessac, France; PAPER: 80/SolidStateChemistry/Regular (Oral) OL SCHEDULED: 14:00/Wed. 29 Nov. 2023/Dreams 4 ABSTRACT: In transition metal fluorides, the fairly strong ionic character of the M-F bonding between fluoride and metal allows a better understanding of most of their electronic properties such as conductivity, transport properties, optical behavior, multiferroism. For example the varied observed magnetic bahiviors: ferro-, antiferro-, ferri-, low-dimensional- magnetisms, can be interpreted easily following the Goodenough superexchange rules[1, 2]. The physicochemical properties of transition metal fluorides can generally be inferred from the types of bonds occurring in the structural networks and connected with the magnetic structures [3]. Inorganic fluorinated materials are found as components in many applications, including energy storage and conversion, photonics, electronics, medicinal chemistry, etc [4]. The strategic importance of these materials will be illustrated by several examples taken from various scientific domains: Fluoride materials used as electrodes in Li-ion batteries and in catalysis / Nanocrystalline fluorides derived from fluorite- (CaF2) or tysonite- (LaF3) types used as solid electrolytes in All-solid-state batteries utilizing the high mobility of F- anions / Rare-earth based fluorides used as up- and down-conversion luminophores, at the micro- or nanoscale / Multiferroic d-transition metal fluorides derived from the perovskite, i.e. layered BaMF4 or TTB-K3Fe5F15, in which magnetism and ferroelectricity coexist / Fluorine-based superconductors obtained by F-doping in cuprate systems La2CuO4 and Sr2CuO3 or in F-doped oxypnictide LnFePnO1-xFx [5]. Finally, solid-state inorganic nanofluorides are used in many other advanced domains such as dye-sensitized solar cell, transparent conducting films, solid state lasers, nonlinear optics, UV absorbers, frequency doubling. Their role is also decisive in medicine and biotechnologies, where nano-crystals of doped rare-earth fluorides can be used as theranostic nano-agents integrating both imaging probes and therapeutic media, and are therefore able to perform diagnostic and therapy within a single nano-object. References: [1] Magnetism and the Chemical Bond, J. B. Goodenough, Interscience Publ. (1963) [2] Crystal chemistry and magnetic properties of CrIIBIIIF5 compounds, A. Tressaud, J.M. Dance, J. Ravez, J. Portier, P. Hagenmuller, J.B. Goodenough, Mat. Res. Bull., 8, 1467, (1973). [3] Crystal Chemistry and Selected Physical Properties of Inorganic Fluorides and Oxide-Fluorides, M. Leblanc, V. Maisonneuve, A. Tressaud, Chem. Rev. 115, 1191(2015). [4] Photonic & Electronic Properties of Fluoride Materials, A.Tressaud & K. Poeppelmeier Eds., Vol. 1 “Progress in Fluorine Science”, A. Tressaud Series Editor, Elsevier, (2016). [5] Fluorine, a Paradoxical Element, A. Tressaud, Elsevier (2019). |
