Microscopic evidence for a partially gapped density wave state in {alpha}-(BEDT-TTF){sub 2}KHg(SCN){sub 4} in high magnetic fields.

Journal Article · Mon Feb 01 04:00:00 EST 1999 · Solid State Commun.

DOI:https://doi.org/10.1016/S0038-1098(99)00017-4· OSTI ID:942457

Kuhns, P L; Brooks, J S; Caldwell, T; Moulton, W G; Reyes, A P; Biskup, N; Kini, A M; Schlueter, J A; Wang, H H; Geiser, U; Williams, J M

We present NMR measurements on {alpha}-(BEDt-TTF){sub 2}KHg(SCN){sub 4}, in which the six inner carbon sites of BEDT-TTF are labeled with the {sup 13}C isotope, at low temperatures and in magnetic fields up to 28.8 T. We find, based on microscopic measurements which probe the center of the primary molecular orbital, that the density wave ground state of this system persists up to fields well above the so-called 'kink field', a hysteretic transition observed in transport near 23 T below 6 K. The main implication of this result is that in the low temperature limit, the ground state of this material is not fully metallic, but still partially gapped, even to 28.8 T. We obtain a BCS-like relationship between the transition temperature and the energy gap, as derived from the spin relaxation measurements using a simple model. Further, the {sup 13}C NMR spectrum is relatively insensitive to crossing the phase boundary, a result that does not support the notion that the ground state is a conventional spin density wave ground state.

• Research Organization: Argonne National Laboratory (ANL)
• Sponsoring Organization: SC; NSF
• DOE Contract Number: AC02-06CH11357
• OSTI ID: 942457
• Report Number(s): ANL/CHM/JA-31682
• Journal Information: Solid State Commun., Journal Name: Solid State Commun. Journal Issue: 10 ; Feb. 1999 Vol. 109; ISSN 0038-1098; ISSN SSCOA4
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
DENSITY
ELECTRONIC STRUCTURE
ENERGY GAP
GROUND STATES
MERCURY COMPLEXES
NUCLEAR MAGNETIC RESONANCE
ORGANIC SUPERCONDUCTORS
POTASSIUM COMPLEXES
TRANSITION TEMPERATURE