Transport, magnetic and structural properties of Mott insulator MnV2O4 at the boundary between localized and itinerant electron limit

Abstract

The effect of Zn and Cr doping on the transport and magnetic properties of MnV 2 O 4 have been investigated using resistivity, thermoelectric power (TEP), magnetization, neutron diffraction and X-ray diffraction techniques. It is observed, that with increase in Zn substitution the noncollinear orientation of Mn spins with the V spins decreases which effectively leads to the decrease of structural transition temperature more rapidly than Curie temperature. Investigations also show that with Zn doping both the Curie temperature (T C ) and structural transition temperature (T S ) decrease, while the gap between them increases rapidly. On the other hand, with Cr doping on the V site the T C remains almost constant but T S decreases rapidly. Moreover, with Zn doping both resistivity and TEP decrease, whereas with 10 % Cr doping the TEP decreases and a change of sign occurs indicating an increase in the band gap. This leads to the decrease of the mobility of the polaronic holes than the mobility of the electronic polarons at low temperature.

Effect of dilution of both A- and B- sites on the multiferroic properties of spinal Mott insulators

“…Therefore, the moment of the V sub-lattice also decreases with increasing Li content and increases for Cr content. It is important to compare these with the earlier studies on Zn x Mn 1-x V 2 O 4 [23] and Co 1-x Zn x V 2 O 4 [22] because Zn(0.74Å) is also a non magnetic ion.…”

“…As a result, the magnetic transition is suppressed. 23 Figure 5 shows the temperature dependent electrical polarization for the FeV Li doping the coupling between V-V decreases due to the presence of V 3+ and V 4+ at the octahedral site but Cr 5% doping has no effect on V-V coupling which in effect does not change the onset temperature.…”

“…19 doped at the A site. [21][22][23] Furthermore, Li 1+ is also a non magnetic ion and its size is comparable to Mn, Zn, Fe and Co but Li 1+ has no 3d electron in their outer shell unlike Fe and Co. Therefore, it will be interesting to investigate the magnetic and transport properties by doping Li in CoV 2 O 4 and FeV 2 O 4 at the A site.…”

Pressure induced effects on the chemical and magnetic structure of spinel MnV2O4

“…The combined effect of spin, lattice and orbital degrees of freedom in spinel vanadates AV 2 O 4 (A = Cd, Mn, Mg, Zn) has generated significant interest in the study of these [1][2][3][4][5]. In this spinel structure octahedral V sites form a frustrated pyrochlore lattice in which V 3+ are located at vertices of a network of corner sharing tetrahedra.…”

“…MnV 2 O 4 develops a collinear ferrimagnetic ordering at T N = 56 K, where the magnetic moments of Mn and V align in oppo site directions [3]. At slightly lower temperatures, a struc tural phase trans ition characteristic of AV 2 O 4 systems from a cubic to a tetragonal phase takes place at T S = 53 K, with the spin structure of the V 3+ ions becoming now noncollinear [3][4][5]. The structural transition at 53 K arising from orbital ordering [2,9] is of first order in nature [10] and is found to be influenced by magnetic field [9][10][11] indicating a close correlation between the orbital, spin, and chemical structure in this compound.…”