Impact of inversion and non-stoichiometry on the transport properties of mixed zinc-cobalt ferrites

Abstract

Electrical transport in metal spinel ferrites (MFe2O4, M = transition, earth-alkali, or main group divalent metal) arises from charge carrier hopping between octahedral sites of different oxidation state. This allows...

Identifying different electronic transport mechanisms in nanoporous inorganic electrides – a combined study using Hall measurements and electron paramagnetic resonance spectroscopy

“…Thus, the mobility reveals an exponential dependence on temperature in the high temperature range only, which is typical for hopping transport. 35–38 It is also worth noting that the transition temperatures between the three different transport ranges shift to lower temperatures with increasing effective charge carrier concentration, i.e. , with increasing degree of reduction x .…”

The role of Zn and Ru substitution on the structural, magnetic and dielectric properties of ferrite cuprospinels

“…Such nonstoichiometry may lead to additional charge transfer leading to an overall enhancement of the conductivity of the system. Such charge transfer can be directly probed by the dielectric spectroscopy, especially in frequency dependent ac-conductivity studies [51]. In our investigated systems, Ru is predominantly present in its trivalent oxidation state which can be easily seen from x-ray photoelectron spectroscopy (XPS) data shown in the figure S8 of the supplementary information.…”

Greener synthesis of lightweight, self‐standing PMMA/CoFe2O4 polymeric film for magnetic, electronic, and terahertz shielding applications

“…As rule, cobalt ferrite crystallizes in inverse spinel structure, face‐centered cubic with a large cell parameter 13 . In this configuration, divalent cobalt (Co 2+ ) occupies octahedral sites whereas half of the iron (Fe 3+ ) ions are positioned at tetrahedral sites and the other half at the octahedral sites 14 …”

“…13 In this configuration, divalent cobalt (Co 2+ ) occupies octahedral sites whereas half of the iron (Fe 3+ ) ions are positioned at tetrahedral sites and the other half at the octahedral sites. 14 However, the brittleness, heavy weight, low mechanical strength of ferrites, and detrimental interface reaction of ferrites (namely CoFe 2 O 4 ), introduce serious limitations on their processing and exploitation in various applications, particularly those needs flexible films.…”