Study of dielectric behavior and electrical properties of hematite α-Fe2O3 doped with Zn

Abstract

The effects of Zn-doping on the dielectric behavior and electrical properties of bulk ?-Fe2O3 have been studied. X-ray diffraction analysis revealed the presence of two phases in all samples: hematite and spinel ZnFe2O4, with the amount of spinel phase increasing with increasing Zn content. Scanning electron microscopy analysis combined with energy dispersive X-ray spectroscopy showed that the Zn-bearing phase occurred in the form of individual spinel ZnFe2O4 grains in a hematite matrix. DC conductivity was measured in the temperature range 25-225oC (298-498 K). Impedance spectroscopy measurements in the same temperature range were carried out in the frequency range 100Hz to 10 MHz. Increase in the Zn content resulted in increased electrical conductivity and higher values of the dielectric constant. The resistance and capacitance of grains and grain boundaries were analyzed by modeling the experimental results using an equivalent circuit. [Projekat Ministarstva nauke Republike Srbije, br. III 45014]

Microwave assisted fabrication of a nanostructured reduced graphene oxide (rGO)/Fe2O3 composite as a promising next generation energy storage material

“…50,51 When n ¼ 1, the circuit describes an ideal capacitor, and when n ¼ 0, the circuit describes an ideal resistor. The true capacitance can be resolved from the CPE value by using the following equation:…”

“…51 The inset of Fig. 6 shows the equivalent circuit used for tting the EIS data, using the true capacitance derived from above mentioned equation from the CPE values.…”

The Influence of Ti Doping on Morphology and Photoelectrochemical Properties of Hematite Grown from Aqueous Solution for Water Splitting

“…The carrier density of Ti‐doped nanorod hematite is 1 order of magnitude higher than the pristine one, assuming that the dielectric constant is the same. However, it was reported that doped hematite has a higher dielectric constant . Therefore the actual carrier density enhancement may be less.…”

“…However, it was reported that doped hematite has a higher dielectric constant. [22] Therefore the actual carrier density enhancement may be less. Ti doping greatly enhances the carrier density, which improves the electron conductivity and results in a higher charge separation efficiency in the bulk.…”

Electrical Properties of Tholins and Derived Constraints on the Huygens Landing Site Composition at the Surface of Titan

“…On the other hand, some polymers, such as polyaniline, or in general, nitrile‐rich organic compounds, may be more conductive but their accurate electrical properties remain unknown (Le Gall et al, ). Also, nanophase iron and nanophase hematite which are present in Saturn's rings and on the surface of Iapetus (Clark et al, ) may have relatively high conductivity at low frequencies/low temperatures: Nikolic et al () measured the DC electrical conductivity of hematite doped with Zn, and by extrapolating their results at Titan's surface temperature, the maximum conductivity is found to be 10 −8 S/m; therefore, the possibility that hematite (doped with 10% Zn) as a major component of this layer cannot be excluded but is very low (the highest conductivity value of this component is only slightly higher than the lowest possible conductivity of this layer; additionally, this only applies to hematite with high Zn content, higher than 10%). Although no measurement of electrical properties of nanophase iron relevant to Titan was found in the literature, powdered metals tend to have a high conductivity.…”