The wide variety of properties exhibited by transition metal oxides places them as highly attractive materials, both from a fundamental and an applied point of view. Modern deposition techniques allow us to assemble oxides into epitaxial heterostructures with atomic precision. As a result, one can achieve minute control over the electronic, magnetic, and structural properties, allowing further tuning of oxides' properties and even access to novel electronic behaviors not exhibited by the parent compounds.
Here we will study the structure-property relationship of ferromagnetic double perovskite La2NiMnO6 thin films as their thickness is reduced to a few unit cells [1]. We will also use atomically-controlled La2NiMnO6/Re2NiMnO6 (RE=Nd, Sm) superlattices to explore the length scale of the interfacial coupling between ferromagnetic and paramagnetic phases and show that the magnetic transition temperature can be tuned [2]. Finally, we will also demonstrate how these superlattices enable the rational design of different antipolar distortions, paving the way to the emergency of multiferroicity in these artificially layered systems.
A comprehensive characterization of the structural and electronic properties of the heterostructures will be performed using a variety of techniques (SQUID magnetometry, TEM, XAS, XMCD, low-energy muons, etc.). Landau theory and first-principles calculations will also be presented.
[1] G. De Luca et al., Advanced Materials 34, 2203071 (2022).
[2] J. Spring et al., ACS Nano (in press - arXiv:2406.09937).