%0 Journal Article
%A Solís, Cecilia
%A Somacescu, Simona
%A Palafox, Elena
%A Balaguer, María
%A Serra, José M.
%T Particular Transport Properties of NiFe 2 O 4 Thin Films at High Temperatures
%J The journal of physical chemistry  / C
%V 118
%N 42
%@ 1932-7447
%C Washington, DC
%I Soc.
%M FZJ-2014-05877
%P 24266 - 24273
%D 2014
%X NiFe2O4 (NFO) thin films were deposited on quartz substrates by rf magnetron sputtering, and the influence of the deposition conditions on their physic-chemical properties was studied. The films structure and the high temperature transport properties were analyzed as a function of the deposition temperature. The analysis of the total conductivity up to 800 °C in different pO2 containing atmospheres showed a distinct electronic behavior of the films with regard to the bulk NFO material. Indeed, the thin films exhibit p-type electronic conductivity, while the bulk material is known to be a prevailing n-type electronic conductor. This difference is ascribed to the dissimilar concentration of Ni3+ in the thin films, as revealed by XPS analysis at room temperature. The bulk material with a low concentration of Ni3+ (Ni3+/Ni2+ ratio of 0.20) shows the expected n-type electronic conduction via electron hopping between Fe3+–Fe2+. On the other hand, the NFO thin films annealed at 800 °C exhibit a Ni3+/Ni2+ ratio of 0.42 and show p-type conduction via hole hopping between Ni3+–Ni2+.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000343740300008
%R 10.1021/jp506938k
%U https://juser.fz-juelich.de/record/172397