Shubnikov–de Haas oscillations in the two-dimensional organic conductor τ−(EDO−S,S−DMEDT−TTF)2(AuBr2)1+y(y∼0.75)
Year: 2002
Type: article
Abstract: The quasi-two-dimensional organic $\ensuremath{\tau}$-type conductor, $\ensuremath{\tau}\ensuremath{-}(\mathrm{EDO}\ensuremath{-}S,S\ensuremath{-}\mathrm{DMEDT}\ensuremath{-}\mathrm{TTF}{)}_{2}({\mathrm{AuBr}}_{2}{)}_{1+y}(y\ensuremath{\sim}0.75),$ shows metallic temperature dependence of the resistivity down to ${T}_{\mathrm{min}}\ensuremath{\sim}50\mathrm{K},$ below which resistance upturn is observed. There has been no evidence of the phase transition through ${T}_{\mathrm{min}}.$ In this work, in pursuit of direct evidence for metal at low temperature by transport measurement, we show an observation of the Shubnikov--de Haas (SdH) oscillations for this salt. The observed frequencies of the oscillations are inconsistent with the previous band calculation. Further, it is remarkable that the amplitude of the oscillation was so giant $(|\ensuremath{\Delta}\ensuremath{\rho}/{\ensuremath{\rho}}_{0}|\ensuremath{\sim}30%),$ and the oscillation above 20 T corresponds to a $N=2$ Landau state, i.e., next to a quantum limit. We also observed the SdH oscillations in other $\ensuremath{\tau}$-type conductor, $\ensuremath{\tau}\ensuremath{-}(\mathrm{P}\ensuremath{-}S,S\ensuremath{-}\mathrm{DMEDT}\ensuremath{-}\mathrm{TTF}{)}_{2}({\mathrm{AuBr}}_{2}{)}_{1+y}(y\ensuremath{\sim}0.75),$ which almost reproduced the previous report by Storr et al. [Phys. Rev. B 64, 045107 (2001)].
Language: Latvian
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2048865337