Fermi surface of ferromagneticEuB6

Abstract

We have determined the Fermi surface and effective masses of electronic carriers in ferromagnetic EuB 6 from pulsed field magnetization and steady field torque Landau quantum oscillatory measurements. To aid in the interpretation of the measurements, superconducting quantum interference device magnetometer measurements of the overall magnetization were made on the same samples. The results are consistent with recent electronic structure calculations and show both an electron and a hole pocket located at the X point in the Brillouin zone. ͓S0163-1829͑98͒03945-9͔

Electronic properties ofEuB6in the ferromagnetic regime: Half-metal versus semiconductor

“…Early local density approximation (LDA) 8 as well as recent band structure calculations in LDA+U 9 show an overlap of valence and conduction band around the X-point of the Brillouin zone. Shubnikov -de Haas and de Haas -van Alphen measurements 10,11 agree with that picture as they report electron and hole pockets on the Fermi surface at the X-point. The carrier density is about 0.01 per unit cell for low and 0.001 for higher temperatures.…”

Absence of X-Point Band Overlap in Divalent Hexaborides and Variability of the Surface Chemical Potential

“…Without such overlap stoichiometric divalent hexaborides would be insulators. Band overlap is predicted by band structure calculations 4,5) and de Haas van Alphen (dHvA) and Shubnikov de Hass (ShD) data 6) have been interpreted in this semi-metal framework.…”

“…Without such overlap stoichiometric divalent hexaborides would be insulators. Band overlap is predicted by band structure calculations 4, 5) and de Haas van Alphen (dHvA) and Shubnikov de Hass (ShD) data 6) have been interpreted in this semi-metal framework.Our early angle-resolved photoemission spectroscopy (ARPES) studies of EuB 6 and SrB 6 synchrotron measurements predating the FM discovery, showed, contrary to the band-overlap picture, an isolated X-point electron pocket separated from the X-point boron valence band maximum by a gap >1 eV. However, motivated by the prior theory results, by apparently firm evidence for bulk band overlap from dHvA and SdH data discussed below and by certain surface sensitive aspects of our ARPES data, we interpreted 7) the observed gap as a property only of the surface region probed in ARPES.…”

Fermi surface properties of low-concentrationCexLa1−xBTeklu1, Goodrich2, Harrison3 et al. 2000Phys. Rev. BSelf Cite200130View full textAdd to dashboardCite

“…Single crystals of Ce x La 1−x B 6 with x = 0, 0.01, 0.02, 0.03, 0.04, and 0.05 were grown in Al flux in the shape of rectangular parallelepipeds (1×0.5×2 mm) with each face along a [100] axis of the cubic structure [11]. Most of the dHvA magnetization measurements on these samples were made in a 0−18 T superconducting magnet using the field modulation technique where a small time oscillating field h 0 is superimposed on a steady state field.…”