Effect of Fe doping on high field magnetoresistance and low field magnetoresistance at zero field in polycrystalline La{sub 0.7}Sr{sub 0.3}Mn

Journal Article · Fri Jun 01 04:00:00 EDT 2001 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.1358344· OSTI ID:40204073

Huang, Q; Li, Z W; Li, J; Ong, C K

Polycrystalline La{sub 0.7}Sr{sub 0.3}Mn{sub 1{minus}x}Fe{sub x}O{sub 3} thin films, with x=0{endash}0.12, have been prepared on (001)-Si substrates using pulsed laser deposition. The films consist of fine grains with an average size of 60{endash}80 nm. For those films, the metal{endash}insulator transition temperature, T{sub p}, is much lower than the Curie temperature, T{sub C}. The high field magnetoresistance, HFMR, is nearly temperature independent for x{lt}0.08, whereas the extrapolated low field magnetoresistance at zero field, LFMR{sup *}, decreases rapidly with increasing temperature. Moreover, Fe doping significantly decreases LFMR{sup *} and enhances HFMR at low temperatures. We propose that for the Fe-doped films, both the reduced spin polarization of conduction electrons and the increased spin-flip scattering are responsible for the decrease of LFMR{sup *}, while the weakened ferromagnetic spin interaction at the grain boundaries is responsible for the enhanced HFMR. {copyright} 2001 American Institute of Physics.

• Sponsoring Organization: (US)
• OSTI ID: 40204073
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 11 Vol. 89; ISSN 0021-8979
• Publisher: The American Physical Society
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CURIE POINT
GRAIN BOUNDARIES
MAGNETORESISTANCE
SPIN FLIP
THIN FILMS
TRANSITION TEMPERATURE