Large Magnetothermopower Effect in Dirac Materials (Sr/Ca)MnBi2
We report temperature and magnetic field dependence of the thermal transport properties in single crystals of (Sr/Ca)MnBi2 with linear energy dispersion. In SrMnBi2 thermopower is positive, indicating hole-type carriers and the magnetic field enhances the thermopower significantly. The maximum change of thermopower is about 1600% in 9 T field and at 10 K. A negative thermopower is observed in CaMnBi2 with dominant electron-type carriers, and, in contrast, the magnetic field suppresses the absolute value of thermopower. First-principle band structure shows that the chemical potential is close to the Dirac-cone-like points in linear bands. The magnetic field suppresses the apparent Hall carrier density of CaMnBi2 below 50 K. The large magnetothermopower effect in (Sr/Ca)MnBi2 is attributed to the magnetic field shift of chemical potential.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Sponsoring Organization:
- USDOE SC OFFICE OF SCIENCE (SC)
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 1049249
- Report Number(s):
- BNL-98199-2012-JA; APPLAB; R&D Project: PO-013; KC0202010; TRN: US201217%%583
- Journal Information:
- Applied Physics Letters, Vol. 100, Issue 11; ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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