Related Experiment Video
Updated: Feb 19, 2026
Comparison of Two Different Synthesis Methods of Single Crystals of Superconducting Uranium Ditelluride
Published on: July 8, 2021
Bulk Kosterlitz-Thouless Type Molecular Superconductor β″-(BEDT-TTF)2[(H2O)(NH4)2Cr(C2O4)3]·18-crown-6
Lee Martin1, Jordan R Lopez1, Hiroki Akutsu2
1School of Science and Technology, Nottingham Trent University , Clifton Lane, Nottingham NG11 8NS, United Kingdom.
Abstract:
A new molecular superconductor, β″-(BEDT-TTF)2[(H2O)(NH4)2Cr(C2O4)3]·18-crown-6, has been synthesized from the organic donor molecule BEDT-TTF with the anion Cr(C2O4)33-. 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)33- (layer B), layers of (H2O)(NH4)18-crown-6 (layer C), and layers of NH4+ and Δ-Cr(C2O4)33- (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 suggest 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.
More Related Videos
Related Concept Videos
01:28Types Of Superconductors
01:24Superconductor
02:37Metallic Solids
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...