Search

Abstract: We review recent experimental measurements of the Fermi surface of the iron–pnictide superconductor LaFePO using quantum oscillation techniques. These studies show that the Fermi surface topology is close to that predicted by first principles density functional theory calculations, consisting of quasi-two-dimensional electron-like and hole-like sheets. The total volume of the two hole sheets is almost equal to that of the two electron sheets, and the hole and electron Fermi surface sheets are close to a nesting condition. No evidence for the predicted three-dimensional pocket arising from the Fe band is found. Measurements of the effective mass suggest a renormalisation of around two, close to the value for the overall band renormalisation found in recent angle resolved photoemission measurements. [Copyright &y& Elsevier]

We report high-field magnetotransport measurements on β″-BEDT-TTF4[(H3O)M(C2O4)3]C5H5N, where M=Ga3+, Cr3+ or Fe3+. In spite of the differing M ions, these compounds have very similar Fermi surfaces. We observe four distinct Shubnikov–de Haas frequencies, corresponding to four Fermi-surface pockets; the frequencies exhibit the additive relationship expected for a compensated semimetal. The compounds show paramagnetic behaviour and no superconductivity down to 0.5 K, in contrast to other materials of the same family with different solvent molecules. [Copyright &y& Elsevier]