Synthesis of P-Type and N-Type Nickel Ferrites and Associated Electrical Properties
Physica B: Condensed Matter 2015
Andris Šutka, Rainer Pärna, Tanel Käämbre, Vambola Kisand

We used sol-gel auto combustion to synthesize nickel ferrites of p-type and n-type conductivity by controlling the relative amounts of nickel and iron during synthesis. The obtained samples have been characterized by XRD, FE-SEM, electrical measurements and XPS. We observe huge differences in the effect of grain size on the electrical resistivity between the p-type and the n-type material when the grain size increases from nano to micro scale during annealing at temperatures from 900 oC to 1300 oC. The observed resistivity decrease (due to grain size) is four orders of magnitude in the the n-type nickel ferrite, whereas the p-type material remains virtually unaffected. We rationalize this drastic difference to stem from a reverse contrast of the surface (grain shell) versus bulk (grain core) conductivity between p- and n-type ferrite. With the grain shells in p-type the easier charge carrier path the effect of scatter at grain boundaries is accordingly diminished, whereas in the n-type charge transport properties are controlled by (the number of) grain boundaries in a conduction path.

Atslēgas vārdi
Nickel ferrite, Sol–gel, X-rayphotoelectron spectroscopy

Šutka, A., Pärna, R., Käämbre, T., Kisand, V. Synthesis of P-Type and N-Type Nickel Ferrites and Associated Electrical Properties. Physica B: Condensed Matter, 2015, Vol.456, 232.-236.lpp. ISSN 0921-4526. Pieejams: doi:10.1016/j.physb.2014.09.013

Publikācijas valoda
English (en)
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