The pressure dependence of the interlayer magnetoresistance of the quasi-two dimensional organic metal ${\beta }^{″}{-\left(\mathrm{BEDT}\text{−}\mathrm{TTF}\right)}_4\left(\mathrm{N}{\mathrm{H}}_4\right)\left[\mathrm{Fe}{\left({\mathrm{C}}_2{\mathrm{O}}_4\right)}_3\right]\bullet \mathrm{DMF}$ [where BEDT-TTF represents bis(ethylenedithio)tetrathiofulvalene and DMF is dimethylformamide] has been investigated up to $1\mathrm{GPa}$ in pulsed magnetic fields up to $55\mathrm{T}$. The Shubnikov–de Haas oscillation spectra can be interpreted on the basis of three compensated orbits in the whole pressure range studied, suggesting that the Fermi surface topology remains qualitatively the same as the applied pressure varies. In addition, all the observed frequencies, normalized to their value at ambient pressure, exhibit the same sizable pressure dependence. Despite this behavior, which is at variance with that of numerous charge-transfer salts based on the BEDT-TTF molecule, nonmonotonic pressure-induced variations of parameters such as the scattering rate linked to the various detected orbits are observed.

• Received 18 July 2006

DOI:https://doi.org/10.1103/PhysRevB.74.233104