Chemical pressure effects on structural, magnetic, and transport properties of Mn1−xCoxV

Evolution of the magnetic and structural properties ofFe1−xCoxV2O4

“…This is similar to the chemical pressure effects on Mn 1−x Co x V 2 O 4 . The resistivity studies on Mn 1−x Co x V 2 O 4 [33] have shown that with decreasing V-V distance the system approaches the itinerant electron behavior. The DFT calculation on CoV 2 O 4 [35] then shows that this increasing electronic itinerancy can lessen the magnetic anisotropies and enhance the A-B site's magnetic exchange interactions to increase the CF transition temperature.…”

“…For example, the resistivity and X-ray diffraction (XRD) studies on Mn 1−x Co x V 2 O 4 show that with increasing Codoping, the system approaches the itinerant electron limit with decreasing resistivity [33]. Around x = 0.8, the system shows no structural phase transition down to 10 K [33,34].…”

“…For example, the resistivity and X-ray diffraction (XRD) studies on Mn 1−x Co x V 2 O 4 show that with increasing Codoping, the system approaches the itinerant electron limit with decreasing resistivity [33]. Around x = 0.8, the system shows no structural phase transition down to 10 K [33,34]. Recently, the neutron scattering experiments and first principle calculations have revealed that the strong competition between the orbital ordering and itinerancy in Mn 1−x Co x V 2 O 4 is the key factor for its complex magnetic and structural phase diagram.…”

Determination of transition metal ion distribution in cubic spinel Co1.5Fe1.5O4 using anomalous x-ray diffraction

“…1,2 In various spinel systems, crystallographic coordination, charge/spin states and composition of transition metals play decisive role in structural 3,4 as well as magnetic properties. 4,5 Some interesting phenomena like charge transfer between metals and ligands under hydrostatic pressure, 6 high spin -low spin transition of transition metals under external perturbation, 7 chemical pressure leading to itinerant electron limit 4,8 etc., have been reported in these systems. Transition metals in nature occur in different oxidation (charge) states which usually have different magnetic moments depending on whether it is high-spin (HS), intermediate-spin (IS) or low spin (LS) state.…”

“…Therefore, it would be highly promising to design materials (like Co x Fe 3−x O 4 ) that consists of transition metals with desired magnetic A complete characterization of such a material should have predictive abilities of magnetic properties (magnetic moment, for example). In order to predict the magnetic property, one needs to know (i) the distribution of Co and Fe in tetrahedral and octahedral sites {e.g., value of x in ((Co 4 based on intensity analysis of neutron diffraction peaks. However, in their work, assignment of charge states, based on the value of oxygen positional parameter (u), to the transition metal ions (Co and Fe), is highly speculative.…”