ABSTRACT
Neodymium nickelate, NdNiO3, attracts attention due to the simultaneous occurrence of several phase transitions around the same temperature. The electronic properties of NdNiO3 are extremely complex as structural distortion, electron correlation, charge ordering, and orbital overlapping play significant roles in the transitions. We report the effects of electron and hole injection via doping a single 3d metal, V, in the NdNiO3 nanostructure to understand the variations in the electronic properties without any structural distortion. A reversible resistivity modulation of more than five orders of magnitude via hole doping and complete suppression of the metal to insulator transition via electron doping is observed along with the switching of major charge carriers. The modulation of electronic properties without any structural distortion and external strain opens up new directions to consider the NdNi1-xVxO3 nanostructures applicable as emerging electronic devices.
ABSTRACT
Although, dynamic crystals are attractive for use in many technologies, molecular level mechanisms of various solid-state dynamic processes and their interdependence, remain poorly understood. Here, we report a rare example of a dynamic crystal (1), involving a heavy transition metal, rhenium, with an initial two-face elasticity (within ≈1 % strain), followed by elasto-plastic deformation, at room temperature. Further, these crystals transform to a rotator (plastic) crystal phase at ≈105 °C, displaying exceptional malleability. Qualitative and quantitative mechanical tests, X-ray diffraction, µ-Raman and polarized light microscopy experiments reveal that the elasto-plastic deformation involves both partial molecular rotations and slip, while malleability in the rotator phase is facilitated by reorientational motions and increased symmetry (slip planes). Our work, connecting the plastically bendable (1D or 2D) crystals with the rotator phases (3D), is important for designing multi-functional dynamic crystals.
