Abstract
The properties of correlated oxides can be manipulated by forming short-period superlattices since the layer thicknesses are comparable with the typical length scales of the involved correlations and interface effects. Herein, we studied the metal-insulator transitions (MITs) in tetragonal NdNiO3/SrTiO3 superlattices by controlling the NdNiO3 layer thickness, n in the unit cell, spanning the length scale of the interfacial octahedral coupling. Scanning transmission electron microscopy reveals a crossover from a modulated octahedral superstructure at n = 8 to a uniform nontilt pattern at n = 4, accompanied by a drastically weakened insulating ground state. Upon further reducing n the predominant dimensionality effect continuously raises the MIT temperature, while leaving the antiferromagnetic transition temperature unaltered down to n = 2. Remarkably, the MIT can be enhanced by imposing a sufficiently large strain even with strongly suppressed octahedral rotations. Our results demonstrate the relevance for the control of oxide functionalities at reduced dimensions.
Original language | English |
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Pages (from-to) | 1295-1302 |
Number of pages | 8 |
Journal | Nano letters |
Volume | 21 |
Issue number | 3 |
DOIs | |
Publication status | Published - 10 Feb 2021 |
Keywords
- UT-Hybrid-D
- metal-insulator transition
- nickelate superlattice
- oxygen octahedral rotations
- strain
- dimensionality