ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
There are different models which to try to explain the transport properties of the manganese oxides in terms of magnetic polarons, Zener double exchange and Jahn-Teller distortions of the lattice which is temperature dependent. Using Rutherford backscattering techniques (2–3 MeV He ions) we are measuring the presence of lattice distortions by studying the angular scans in the channeling mode. The angular widths (FWHM) can be used to extract both dynamic and static displacements of the atoms from their equilibrium sites. The technique is extremely powerful in the sense that local uncorrected displacements as small as 0.01 A(ring) from the equilibrium position can be detected. The extraction of the physics from the data is relatively straight forward compared to other techniques such as XRD or neturon scattering. Using a variable temperature backscattering system at our center (one of three or four systems around the world) the angular width (FWHM) is found to exhibit a dramatic change with temperature increasing with decreasing temperature showing a possible correlation with both the transport and magnetic properties. The results suggest a decrease in the lattice disorder with reduced temperature far in excess of what one would predict on the basis of a simple Debye behavior. The reduction in the lattice disorder correlates very well with the resistance vs temperature dependence. A variety of manganese oxide epitaxial thin films grown by pulsed laser deposition have been studied and the data suggests a role for structural distortions in any mechanism to explain the transport properties of these materials. © 1996 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.361720
