Preparation of highly overstoichiometric LaNi5+x (1 <= x <= 4) single-phase films by ion beam sputtering

Citation
F. Cuevas et al., Preparation of highly overstoichiometric LaNi5+x (1 <= x <= 4) single-phase films by ion beam sputtering, J APPL PHYS, 86(12), 1999, pp. 6690-6696
Citations number
43
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF APPLIED PHYSICS
ISSN journal
00218979 → ACNP
Volume
86
Issue
12
Year of publication
1999
Pages
6690 - 6696
Database
ISI
SICI code
0021-8979(199912)86:12<6690:POHOL(>2.0.ZU;2-2
Abstract
Single-phase LaNi6.1 and LaNi9.2 films with hexagonal TbCu7 structure have been successfully obtained. Films in the micron scale range were deposited by ion beam sputtering on sapphire and glass substrates heated at 600 K. A two-material La-Ni mosaic target was used for this purpose. X-ray diffracti on and transmission electron microscopy investigations show that the lattic e parameters of the hexagonal structure follow a linear dependence for Ni c oncentration. This result relates to a random substitution of La atoms for Ni dumbbell pairs in the ordered CaCu5 structure. The films exhibit a stron g preferential orientation, with the c axis parallel to the substrate plane , which seems to be favored by the presence of Ni dumbbell pairs. The expec ted impact of this phase on the preparation of new hydrogen storage materia ls is discussed. (C) 1999 American Institute of Physics. [S0021-8979(99)050 24-0].