Electrical transport and magnetic properties of Nd1−xNaxMnO3 manganites

Magnetic properties of Nd1−xKxMnO3 compounds

“…The typical XRD pattern along with Rietveld refinement is shown in Table 1. The lattice parameters are found to be larger than those reported for Na-and Ag-doped Nd-Mn-O series [24][25][26]31].The lattice parameters a and c are found to increase with doping and on the other hand no systematic variation in parameter b has been observed. This can be understood on the basis of competition between larger K 1+ ions replacing Nd 3+ ions and the generation of smaller Mn 4+ ions at the expense of larger Mn 3+ ions.…”

“…It was also predicted that in these materials, Nd ions order antiferromagnetically with spin canting. Recently, the monovalent alkali-ion-doped Nd 1Àx Na x MnO 3 series was studied by a few groups for x ¼ 0.1-0.25 and found that these materials exhibit charge ordering at around 180 K followed by weak FM transition at 110 K [24][25][26]. The electrical resistivity follows semiconducting behavior without any metal-insulator transition.…”

“…The electrical resistivity follows semiconducting behavior without any metal-insulator transition. However, metalinsulator transition could be induced by the application of magnetic field of the order 3 T [26].…”

Charge disproportionation in AlV2O4: A first-principles study

“…Transition metal compounds display abundant peculiar physical properties which have been confusing people a long time, such as the charge disproportionation or charge order of the transition metal [1][2][3][4], the colossal magnetoresistance [5][6][7], unconventional superconductivity [8], etc. The charge, spin, and orbital degrees of freedom of electron in transition metal compound are often strong coupled [9], which make the problem much complicated.…”

Electrical behavior of some silver-doped lanthanum-based CMR materials

“…According to this model, the sample LA-10 can be considered as a mixed-phase system with intrinsic magnetic inhomogeneity as a result of the competition between AFM superexchange and FM doubleexchange interaction. The FM and CO clusters coexist at low temperatures, and when the field is applied, these CO clusters will collapse, resulting in further increase of FM regions which in turn lowers the resistivity [23] thereby exhibiting large MR.…”