TY  - JOUR
AU  - Solís, Cecilia
AU  - Somacescu, Simona
AU  - Palafox, Elena
AU  - Balaguer, María
AU  - Serra, José M.
TI  - Particular Transport Properties of NiFe 2 O 4 Thin Films at High Temperatures
JO  - The journal of physical chemistry  / C
VL  - 118
IS  - 42
SN  - 1932-7447
CY  - Washington, DC
PB  - Soc.
M1  - FZJ-2014-05877
SP  - 24266 - 24273
PY  - 2014
AB  - 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+.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000343740300008
DO  - DOI:10.1021/jp506938k
UR  - https://juser.fz-juelich.de/record/172397
ER  -