Room temperature magnetoresistive response in CMR perovskite manganite thin films
- Advanced Technology Materials, Inc., Danbury, CT (United States). Advanced Delivery and Chemical Systems Div.
Perovskite-structured La{sub x}Sr{sub y}MnO{sub 3} thin-films have been deposited onto LaAlO{sub 3} substrates via liquid delivery chemical vapor deposition (LD-CVD) using metal({beta}-diketonato) precursors, M(thd){sub x} [where M = Ca, Sr, La and Mn, thd = 2,2,6,6-tetramethyl-3,5-heptanedionato and x = 2--3]. Thin films were deposited at temperatures between 500 and 700 C and subsequently annealed at 1,000 C under O{sub 2}. These films possess stoichiometries that are: (1) vastly different from the La{sub 0.67}Sr{sub 0.33}MnO{sub 3} compositions commonly reported in the literature and (2) display high temperature, low field responses that may be technologically important. Resistance versus temperature measurements revealed a metal to semiconductor transition at room temperature and above. Hall measurements on a film of La{sub 0.35}Sr{sub 0.24}MnO{sub 3} displayed a magnetoresistive response (MR) of {minus}10% at 57 C in a fixed magnetic field of 780 Oe. Based upon the research, the observed film properties are directly related to the deposited film stoichiometry and the best results were observed at Sr/La ratios between 0.30 and 1.0 for A-site deficient La{sub x}Sr{sub y}MnO{sub 3} thin-films after thermal annealing.
- OSTI ID:
- 323408
- Report Number(s):
- CONF-971201--; ISBN 1-55899-399-1
- Country of Publication:
- United States
- Language:
- English
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