Structural characterization and magnetoresistance of manganates thin films and Fe-doped manganates thin films

• Published in: Applied surface science Vol. 252; no. 13; pp. 4599 - 4603
• Main Authors: Canulescu, S., Lippert, Th, Grimmer, H., Wokaun, A., Robert, R., Logvinovich, D., Weidenkaff, A., Doebeli, M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 30-04-2006; Elsevier Science
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport phenomena in thin films and low-dimensional structures; Exact sciences and technology; Fe-doped manganates thin films; Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects); Laser deposition; Magnetoresistance; Manganates thin films; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Pulsed laser deposition; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Manganates thin films; Fe-doped manganates thin films; Pulsed laser deposition; Magnetoresistance; Atomic force microscopy; RBS; Crossed beams; Magnetic field effects; Doped materials; Hall effect; Perovskites; XRD; Fabrication property relation; Film growth; Surface structure; Thin films; Manganates; Iron additions; Pulsed beam; Semiconductor metal transition
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2005.07.151

Perovskites thin films with the composition La
0.6Ca
0.4MnO
3 doped with 20% Fe, were prepared by pulsed reactive crossed beam laser ablation, where a synchronized reaction gas pulse interacts with the ablation plume. The films were grown on various substrates and the highest colossal magnetoresistance ratio (CMR) was detected by Hall measurements for films grown on LaAlO
3 (1
0
0), which was selected as substrate for further investigations.
Several growth parameters, such as substrate temperature and target to substrate distance were varied to analyze their influence on the film properties.
The structure of the deposited thin films was characterized by X-ray diffraction and atomic force microscope, while Rutherford backscattering (RBS) was used to determine the film stoichiometry. The electrical properties were determined by Hall effect measurements in a magnetic field of 0.51
T.
These measurements reveal that the amplitude of the CMR ratio depends strongly on the substrate and that the oxygen content influences the temperature where the transition from semiconductor to metal is observed.