3 research outputs found
Small-polaron hopping conductivity in bilayer manganite LaSrMnO
We report anisotropic resistivity measurements on a
LaSrMnO single crystal over a temperature range
from 2 to 400 K and in magnetic fields up to 14 T. For K, the
temperature dependence of the zero-field in-plane resistivity
obeys the adiabatic small polaron hopping mechanism, while the out-of-plane
resistivity can be ascribed by an Arrhenius law with the same
activation energy. Considering the magnetic character of the polarons and the
close correlation between the resistivity and magnetization, we developed a
model which allows the determination of . The excellent
agreement of the calculations with the measurements indicates that small
polarons play an essential role in the electrical transport properties in the
paramagnetic phase of bilayer manganites.Comment: 4 pages, 3 figures, to appear in Physical Review
Extrinsic Magnetotransport Phenomena in Ferromagnetic Oxides
This review is focused on extrinsic magnetotransport effects in ferromagnetic
oxides. It consists of two parts; the second part is devoted to an overview of
experimental data and theoretical models for extrinsic magnetotransport
phenomena. Here a critical discussion of domain-wall scattering is given.
Results on surfacial and interfacial magnetism in oxides are presented.
Spin-polarized tunnelling in ferromagnetic junctions is reviewed and
grain-boundary magnetoresistance is interpreted within a model of
spin-polarized tunnelling through natural oxide barriers. The situation in
ferromagnetic oxides is compared with data and models for conventional
ferromagnets. The first part of the review summarizes basic material
properties, especially data on the spin-polarization and evidence for
half-metallicity. Furthermore, intrinsic conduction mechanisms are discussed.
An outlook on the further development of oxide spin-electronics concludes this
review.Comment: 133 pages, 47 figures, submitted to Rep. Prog. Phy