Surface pattern and large low-field magnetoresistance in La0.5Ca0.5MnO3 films

Authors
Peng, HB Zhao, BR Xie, Z Lin, Y Zhu, BY Hao, Z Ni, YM Tao, HJ Dong, XL Xu, B
Citation
Hb. Peng et al., Surface pattern and large low-field magnetoresistance in La0.5Ca0.5MnO3 films, APPL PHYS L, 74(11), 1999, pp. 1606-1608
Citations number
16
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
APPLIED PHYSICS LETTERS
ISSN journal
00036951 → ACNP
Volume
74
Issue
11
Year of publication
1999
Pages
1606 - 1608
Database
ISI
SICI code
0003-6951(19990315)74:11<1606:SPALLM>2.0.ZU;2-M
Abstract
Formation of an ordered surface structure in La0.5Ca0.5MnO3 films due to th e mismatch of the thermal expansion coefficient between the film and the su bstrate has been investigated. The surface pattern consists of grain chains located on regular orthogonal cracks. The cracks serve as weak-link grain boundaries, and unusually enhanced low-field magnetoresistance (-14.4% in 4 00 Oe at 90 K) has been observed, which may be explained by spin-polarized tunneling across the grain boundaries. (C) 1999 American Institute of Physi cs. [S0003-6951(99)02311-6].