| We have performed a spin-dependent 2D-ACAR study of a single crystal sample of La0.7Sr0.3MnO3 (a manganite perovskite that exhibits colossal magnetoresistance). Measurements were made at three well-separated temperatures, two of which were below the ferromagnetic to paramagnetic transition temperature. It is believed that these measurements constitute the first detailed experimental study of the electronic structure of this material. Of the many properties of the electronic structure of a material, the Fermi surface is one of the most important.; The most recent self-consistent band structure and momentum density calculations predict La0.7Sr0.3MnO3 to have only two significant Fermi surface features, large R-centered cubic hole pockets and a Γ-centered electron spheroid. Both of these features result from the Fermi level crossing majority bands. The Fermi level sits only slightly above a gap in the minority bands, that is, those bands behave as in an semi-conductor. As a result, electron transport is largely spin-polarized and the material is referred to as being nearly half-metallic.; These theoretical predictions are supported by the results of the experimental measurements. Clear indications of the large cubic Fermi surface are observed in our data and, although some evidence is also seen for the electron spheroid, this is decidedly weaker. The experimental results also qualitatively support the supposed spin-polarized transport in this material. This agreement between experiment and theory indicate that the theoretical description is, to a large degree, valid. |
