Anisotropic low-field magnetoresistance of polycrystalline manganite sensors

Citation
Yh. Xu et al., Anisotropic low-field magnetoresistance of polycrystalline manganite sensors, APPL PHYS L, 74(17), 1999, pp. 2513-2515
Citations number
11
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
APPLIED PHYSICS LETTERS
ISSN journal
0003-6951 → ACNP
Volume
74
Issue
17
Year of publication
1999
Pages
2513 - 2515
Database
ISI
SICI code
0003-6951(19990426)74:17<2513:ALMOPM>2.0.ZU;2-0
Abstract
Magnetic-field sensors of bulk La0.67Sr0.33MnO3 and La0.67Ba0.33MnO3 were f abricated. The investigations show that a large low-field magnetoresistance (MR) is exhibited by the polycrystalline samples. MR ratios of the sensors as large as 20% at 77 K and 1.5% at 298 K were observed in fields of 700 O e. Corresponding field sensitivities as high as 170%/T at 3 mT and 298 K, a nd 700%-960%/T at 3-8 mT and 77 K were obtained. The low-field MR is associ ated with intergranular transport of spin-polarized electrons. It is found to be highly anisotropic. The phenomenon is discussed in terms of spin-pola rized transport through two kinds of grain boundaries. These represent two extremes of grain-boundary environments. (C) 1999 American Institute of Phy sics. [S0003-6951(99)04017-6].