De Haas—van Alphen measurements in the ferromagnetic compoundsU3P4andU3As4

Abstract

de Haas---van Alphen measurements are reported for the ferromagnetic actinide compounds ${\mathrm{U}}_{3}$${\mathrm{P}}_{4}$ and ${\mathrm{U}}_{3}$${\mathrm{As}}_{4}$. The large effective masses indicate $f$-electron interaction with conduction bands. The data are interpreted in terms of a semimetallic band structure producing a large electron sheet at point $\ensuremath{\Gamma}$ which is compensated by several smaller hole pockets along the $\ensuremath{\Gamma}\ensuremath{-}P$ line. The measured internal field is much smaller than expected on the basis of magnetization measurements. Several discrepancies with other measurements point to additional unobserved pieces of the Fermi surface.