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The angular magnetothermoelectric power of a charge density wave system
D Krstovska1, E S Choi, E Steven
1National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA. krstovska@magnet.fsu.edu
Summary
Magnetothermopower was studied in an organic salt below and above its phase transition. Both Seebeck and Nernst effects showed resonant behavior, indicating Fermi surface nesting mechanisms in different electronic states.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Organic Electronics
Background:
- Organic charge transfer salts exhibit complex electronic phases.
- Magnetothermopower measurements probe electronic properties under magnetic fields.
- α-(ET)(2)KHg(SCN)(4) is a model system for studying phase transitions and electronic instabilities.
Purpose of the Study:
- Investigate the angular dependence of magnetothermopower in α-(ET)(2)KHg(SCN)(4).
- Analyze thermoelectric effects (Seebeck and Nernst) across different electronic phases (CDW (0), CDW (x), metallic).
- Determine the influence of magnetic fields and temperature on these thermoelectric properties.
Main Methods:
- Angular-dependent magnetothermopower measurements.
- Utilized longitudinal thermoelectric measurements.
- Applied magnetic fields up to 25 T and temperatures below 9 K.
Main Results:
- Both interlayer thermopower (Seebeck effect) and transverse thermopower (Nernst effect) were observed with large amplitudes in all studied phases.
- Thermoelectric effects exhibited resonant-like behavior without sign reversal at specific angles.
- The resonant behavior was most pronounced in the CDW (0) state, suggesting Fermi surface nesting.
- Distinct angular dependencies were noted for thermopower and Nernst effect in the high magnetic field CDW (x) state.
Conclusions:
- The study reveals complex thermoelectric responses in α-(ET)(2)KHg(SCN)(4) across its phase diagram.
- Fermi surface nesting plays a significant role in the observed resonant magnetothermopower phenomena.
- The findings highlight the distinct electronic behaviors in different charge density wave and metallic states under magnetic fields.
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