Semimetallic and charge-ordered α-(BEDT-TTF)2I3: On the role of disorder in dc transport and dielectric properties

Znanstveni rad - Izvorni znanstveni rad

• Autor: Tomislav Ivek; MBZ: 261996
• Autor: Matija Čulo; MBZ: 315094
• Autor: Marko Kuveždić; MBZ: 352683
• Autor: Eduard Tutiš; MBZ: 18035
• Autor: Mario Basletić; MBZ: 197593
• Autor: Branimir Mihaljević
• Autor: Emil Tafra; MBZ: 248700
• Autor: Silvia Tomić; MBZ: 65594
• Autor: Anja Löhle
• Autor: Martin Dressel
• Autor: Dieter Schweitzer
• Autor: Bojana Korin-Hamzić
• Autorova ustanova: Sveučilište u Zagrebu; Prirodoslovno-matematički fakultet; (Fizički odsjek)
• Znanstveno / umjetničko područje, polje i grana: PRIRODNE ZNANOSTI; Fizika

Sažetak (engleski)

α-(BEDT-TTF)2I3 is a prominent example of charge ordering among organic conductors. In this work, we explore the details of transport within the charge-ordered as well as semimetallic phase at ambient pressure. In the high-temperature semimetallic phase, the mobilities and concentrations of both electrons and holes conspire in such a way to create an almost temperature-independent conductivity as well as a low Hall effect. We explain these phenomena as a consequence of a predominantly interpocket scattering which equalizes mobilities of the two types of charge carriers. At low temperatures, within the insulating charge-ordered phase two channels of conduction can be discerned: a temperature-dependent activation, which follows the mean-field behavior, and a nearest-neighbor-hopping contribution. Together with negative magnetoresistance, the latter relies on the presence of disorder. The charge-ordered phase also features a prominent dielectric peak which bears a similarity to relaxor ferroelectrics. Its dispersion is determined by free-electron screening and pushed by disorder well below the transition temperature. The source of this disorder can be found in the anion layers which randomly perturb BEDT-TTF molecules through hydrogen bonds.

• Ključne riječi (engleski): organic conductor; BEDT-TTF; charge order; semimetal; Hall effect; inter-pocket scattering; temperature-dependent gap; hopping conductivity; negative magnetoresistance; disorder; relaxor-like ferroelectric
• Jezik: engleski
• Vrsta publikacije: Znanstveni rad - Izvorni znanstveni rad
• Status objave: Objavljen
• Vrsta recenzije: Recenziran - međunarodna recenzija
• Verzija publikacije: Objavljena verzija rada (izdavačev PDF)
• Naslov časopisa: Physical Review B
• Brojčani podaci: vol. 96, br. 7, 075141
• p-ISSN: 2469-9950
• e-ISSN: 2469-9969
• DOI: https://doi.org/10.1103/PhysRevB.96.075141
• URN:NBN: urn:nbn:hr:217:056541
• Datum objave publikacije: 2017
• Projekt: Šifra: IP-2013-11-1011; Naziv (hrvatski): Jako korelirani elektroni u slojnim organskim materijalima i manganitima: niskofrekventna pobuđenja i nelinearna dinamika; Kratica: SCEinLOM; Voditelj: Silvia Tomić; Pravna nadležnost: Hrvatska; Financijer: HRZZ; Linija financiranja: IP
• URL dokumenta: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.96.075141
• Vrsta resursa: Tekst
• Prava pristupa: Otvoreni pristup
• Javna napomena: © 2017 American Physical Society. Received 8 March 2017. Revised manuscript received 11 July 2017. Published 21 August 2017.
• Datum i vrijeme pohrane: 2020-02-29 18:42:33