Deuteration Effects on the Transport Properties of (TMTTF)₂<i>X</i> Salts

• Main Authors: Andrea Rohwer, Martin Dressel, Toshikazu Nakamura
• Format: Article
• Language: English
• Published: MDPI AG 2020-11-01
• Series: Crystals
• Subjects: charge-transfer salts; (TMTTF)₂X; deuteration; anions; charge transport
• Online Access: https://www.mdpi.com/2073-4352/10/12/1085

The electronic properties in the quasi-one-dimensional Fabre salts are strongly affected by electronic correlations along the molecular stacks, but also by the interactions with the anions located in a cage that is formed by the methyl end groups. We systematically compare the charge transport in deuterated and protonated (TMTTF)<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula><i>X</i> salts with the anions <i>X</i> = Br, PF<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>6</mn></msub></semantics></math></inline-formula>, SbF<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>6</mn></msub></semantics></math></inline-formula>, and ClO<inline-formula><math display="inline"><semantics><msub><mrow></mrow><mn>4</mn></msub></semantics></math></inline-formula>, ranging from Mott and Efros–Shklovskii variable-range hopping to activated band transport with a temperature dependent energy gap. The strong dependence of charge localization and ordering on the anion size and deuteration confirms the subtle structural involvement of the anions in the charge transport along the TMTTF stack.