Searching for crystallographic superstructures in kappa-(BEDT-TTF){sub 2}Cu[N(CN){sub 2}]Br.

Journal Article · Fri Jan 01 04:00:00 EST 2010 · Physica B

DOI:https://doi.org/10.1016/j.physb.2010.01.115· OSTI ID:994054

Wolter, A U. B.; Feyerherm, R; Dudzik, E; Sullow, S; Strack, Ch; Lang, M; Schweitzer, D; Schlueter, J A

To resolve a superstructure formation previously reported for the organic superconductor {kappa}-(BEDT-TTF){sub 2}Cu[N(CN){sub 2}]Br, we present synchrotron x-ray diffraction experiments carried out at the MAGS beamline at BESSY, Helmholtz-Centre Berlin. Surprisingly, in our low temperature (28 K) experiments, when searching k-space at (h 0 3.5), h = 7, 8 and (h 0 0.5), h = 5, 7, for none of these spots we could detect scattering intensity associated to a superstructure formation, in contradiction to previous reports. Our data suggest that details of the structural properties of {kappa}-(BEDT-TTF){sub 2}Cu[N(CN){sub 2}]Br - such as superstructure formation - sensitively depend on sample handling, e.g., cooling rates (in our case 4 K/min), or thermal cycling. A direct relationship between superstructure formation and terminal ethylene group ordering cannot be verified, disproving proposals put forth previously.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 994054
• Report Number(s): ANL/MSD/JA-65642
• Journal Information: Physica B, Journal Name: Physica B Journal Issue: 2010 Vol. 405; ISSN 0921-4526
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

43 PARTICLE ACCELERATORS
ETHYLENE
ORGANIC SUPERCONDUCTORS
SCATTERING
SYNCHROTRONS
THERMAL CYCLING
X-RAY DIFFRACTION