https://doi.org/10.1140/epjb/e2003-00301-6
Effects of vacuum annealing on the transport property of La0.67Sr 0.33MnO3-δ films
1
State Key Laboratory for Magnetism, Institute of Physics and
Center for Condensed Matter Physics, The
Chinese Academy of Sciences, Beijing 100080, P.R. China
2
Department of Physics, The Chinese University of Hong Kong, Hong Kong, P.R. China
Corresponding author: a jrsun@g203.iphy.ac.cn
Received:
11
April
2003
Revised:
8
August
2003
Published online:
24
October
2003
Effects of oxygen content on the transport behavior of epitaxial La2/3Sr
1/3MnO films on (110) NdGaO3 and (001) SrTiO3
substrates have been experimentally studied. A quantitative relation between
the temperature of metal-to-insulator transition (Tp) and the content
of oxygen vacancies is established, and it is found that oxygen
non-stoichiometry causes a monotonic decrease of Tp. A comparison to
crystals La
SrxMnO3 indicates that the reduction of hole
concentration due to the incorporation of anionic vacancies dominates the
variation of Tp, while the vacancies themselves influence the detailed
features of the Tp-
dependence. Strain in the film affects the
effects of oxygen deficiency, and the metal-to-insulator transition
disappears at a smaller
value in tensily stressed films. In the
temperature region above Tp, oxygen vacancies affect the resistive
behavior of the films mainly by modulating the content of Mn4+. In
contrast, extra effects due to the scattering of oxygen vacancies become
important at low temperatures, causing an exponential increase of
resistivity with
. A further analysis indicates that oxygen
deficiency enhances magnetic scattering, and leads to a resistivity upturn
of the form
when
is significant.
PACS: 75.30.-m – Intrinsic properties of magnetically ordered materials / 73.50.-h – Electronic transport phenomena in thin films / 68.60.-p – Physical properties of thin films, nonelectronic
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2003