Lattice effects on the magnetoresistance in doped manganese perovskites (abstract)
- AT&T Bell Laboratories, Murray Hill, New Jersey 07974 (United States)
A detailed study of doped LaMnO{sub 3} with fixed carrier concentration has revealed a direct relationship between the Curie temperature {ital T}{sub {ital c}} and the average ionic radius of the La site {l_angle}{ital r}{sub {ital A}}{r_angle}, which is varied by substituting rare earths of different ionic radii for La. With decreasing {l_angle}{ital r}{sub {ital A}}{r_angle} magnetic order and significant magnetoresistance occur at lower temperatures with increasing temperature hysteresis, and the magnitude of the magnetoresistance increases dramatically. The predominant structural effect of decreasing {l_angle}{ital r}{sub {ital A}}{r_angle} is to decrease the Mn{endash}O{endash}Mn bond angle, which is accompanied by slight variations in the Mn{endash}O bond distance. These results demonstrate that the notion of {open_quote}{open_quote}double exchange{close_quote}{close_quote} must be generalized to include changes in the Mn{endash}Mn electronic hopping element as a result of microstructural changes induced by composition, temperature and pressure variations. {copyright} {ital 1996 American Institute of Physics.}
- OSTI ID:
- 279988
- Report Number(s):
- CONF-951101--
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 79; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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