Doubling of the phase transition temperature of VO2 by Fe doping

Jean-Louis Victor (1) , Manuel Gaudon (1) , Giorgio Salvatori (1) , Olivier Toulemonde (1) , Nicolas Penin (1) , Aline Rougier (1)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

Vanadium dioxide (VO2) undergoes a fully reversible first-order metal–insulator transition from the M1 monoclinic phase (P21/c) to a high-temperature tetragonal phase (P42/mnm) at around 68 °C. Modulation of the phase transition of VO2 by chemical doping is of fundamental and technological interest. Here, we report the synthesis of highly crystallized Fe-doped VO2 powders by a carbo-thermal reduction process. The impact of Fe doping on the structural and phase transition of VO2 is studied. The as-prepared Fe-doped VO2 samples crystallize in the M2 monoclinic form (C2/m), which is linked to segregation of the doping ions in the V2 zigzag chains. A large increase in the transition temperature to 134 °C is observed, which does correspond to a breakthrough in VO2-type thermochromic materials.

Mots clés: Impurities; Granular materials; Differential scanning calorimetry; Phase transitions; Doping

Domaines: Matériaux

Jean-Louis Victor, Manuel Gaudon, Giorgio Salvatori, Olivier Toulemonde, Nicolas Penin, et al.. Doubling of the phase transition temperature of VO2 by Fe doping. Journal of Physical Chemistry Letters, 2021, 12 (32), pp.7792-7796. ⟨10.1021/acs.jpclett.1c02179⟩. ⟨hal-03326220⟩