Indications for the coexistence of closed orbit and quantum interferometer with the same cross section in the organic metal β'-(T)4(H3O)[Fe(C2O4)3] C6H4Cl2: persistence of Shubnikov-de Haas oscillations above 30 K

摘要

Shubnikov-de Haas (SdH) and de Haas-van Alphen (dHvA) oscillations spectra of the quasi-two dimensional charge transfer salt β"-(ET)4(H3O)[Fe(C2O4)3] C6H4C12 have been investigated in pulsedmagnetic fields up to 54 T. The data reveal three basic frequencies Fa, Fb and Fb-a, which can be inter-preted on the basis of three compensated closed orbits at low temperature. However a very weak thermaldamping of the Fourier component Fb, with the highest amplitude, is evidenced for SdH spectra aboveabout 6 K. As a result, magnetoresistance oscillations are observed at temperatures higher than 30 K. Thisfeature, which is not observed for dHvA oscillations, is in line with quantum interference, pointing to aFermi surface reconstruction in this compound.