Superconducting super-organized nanoparticles of the superconductor (BEDT-TTF)2Cu(NCS)2

Dominique de Caro (1) , Kane Jacob (1) , Marco Revelli-Beaumont (1) , Christophe Faulmann (2) , Lydie Valade (1) , Marine Tassé (1) , Sonia Mallet-Ladeira (3) , Shuxiang Fan (4) , Tadashi Kawamoto (4) , Takehiko Mori (4) , Jordi Fraxedas (5)

1 LCC - Laboratoire de chimie de coordination
2 CEMES - Centre d'élaboration de matériaux et d'études structurales
3 ICT - Institut de Chimie de Toulouse
4 TITECH - Tokyo Institute of Technology [Tokyo]
5 ICN2 - ICN2 - Institut Catala de Nanociencia i Nanotecnologia

The synthesis of (BEDT-TTF)2Cu(NCS)2 in the presence of poly(ethylene glycol) leads to super-organized nanoparticles of 2–8 nm size. Samples contain crystalline nanoparticles of the κ-(BEDT-TTF)2Cu(NCS)2 phase. The electrical conductivity at room temperature is about 0.08 S · cm–1, a typical value for nanopowders of tetrathiafulvalene-based conducting compounds. The current-voltage characteristic for an individual nanoparticle aggregate is fitted with a Shockley diode model. A saturation current of 4.1 pA and a threshold voltage of 0.45 V are extracted. N1s and S2p lines in X-ray photoelectron spectroscopy evidence a charge transfer, characteristic for tetrathiafulvalene-based conducting salts. Magnetic susceptibility studies show a superconducting transition at 9.1 K, a characteristic value for the κ-(BEDT-TTF)2Cu(NCS)2 phase. The thermoelectric power of the nanopowder is represented by the average //c and //b values for the single-crystal. Finally, resistivity for the nanopowder is nearly flat in the metallic region.

Mots clés: Molecular conductor; superconductor; nanoparticles

Domaines: Chimie de coordination; Matériaux; Supraconductivité [cond-mat.supr-con]; Science des matériaux [cond-mat.mtrl-sci]

Dominique de Caro, Kane Jacob, Marco Revelli-Beaumont, Christophe Faulmann, Lydie Valade, et al.. Superconducting super-organized nanoparticles of the superconductor (BEDT-TTF)2Cu(NCS)2. Synthetic Metals, 2021, 278 (16), pp.116844. ⟨10.1016/j.synthmet.2021.116844⟩. ⟨hal-03364488⟩