Bulk Kosterlitz–Thouless type molecular superconductor β″-(BEDT-TTF)2[(H2O)(NH4)2Cr(C2O4)3]·18-crown-6

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Martin, L. ORCID: 0000-0002-5330-5700, Lopez, J.R., Akutsu, H., Nakazawa, Y. and Imajo, S., 2017. Bulk Kosterlitz–Thouless type molecular superconductor β″-(BEDT-TTF)2[(H2O)(NH4)2Cr(C2O4)3]·18-crown-6. Inorganic Chemistry. ISSN 0020-1669

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Official URL: http://doi.org/10.1021/acs.inorgchem.7b02171

Abstract

A new molecular superconductor, β”-(BEDTTTF)2[(H2O)(NH4)2Cr(C2O4)3].18-crown-6, has been synthesized from the organic donor molecule BEDT-TTF with the anion Cr(C2O4)3 3- . The crystal structure consists of conducting organic layers of BEDT-TTF molecules which adopt the β” packing motif (layer A), layers of NH4 + and Λ-Cr(C2O4)3 3- (layer B), layers of (H2O)(NH4)18- crown-6 (layer C), and layers of NH4 + and Δ-Cr(C2O4)3 3- (layer D) which produce a superstructure with a repeating pattern of ABCDABCDA. As a result of this packing arrangement this is the 2D superconductor with the widest gap between conducting layers where only a single donor packing motif is present (β”). Superconducting critical temperatures at ambient pressure observed by electrical transport and magnetic measurements are 4.0- 4.9 and 2.5 K, respectively. The strong 2D nature of this system, the broad transition to Tzero at 1.8K, and the transition of α of V ∝ Iα from 1 to 3 on I-V curves strongly suggests that the superconducting transition is very close to a Kosterlitz-Thouless transition. The magnetic field dependence of the superconducting critical temperature parallel to the conducting plane gives an upper critical field μ0Hc2// > 8 T, which is over the calculated Pauli-Clogston limit for this material.

Item Type:

Journal article

Publication Title:

Inorganic Chemistry

Creators:

Martin, L., Lopez, J.R., Akutsu, H., Nakazawa, Y. and Imajo, S.

Publisher:

American Chemical Society

Date:

9 November 2017

ISSN:

0020-1669