Promising strategy uses atomic displacements to control the quantum properties of a vanadate perovskite

Perovskites, materials with a crystal structure similar to that of the mineral calcium titanate CaTiO₃, have properties that are beneficial for the development of various technologies. For example, they have proven promising in the development of photovoltaic (PV) systems and electronic devices.

Perovskites are also ideal materials for exploring a variety of quantum states, including orbital order, magnetism and superconductivity. Additionally, physicists can carefully engineer these materials to unlock various tunable properties, typically resulting from subtle deviations from the cubic perovskite structure.

Detecting and controlling these deviations to achieve certain characteristics can be a major challenge. In a recently published article in Natural physicsResearchers at the Max Planck Institute for Solid State Research presented a promising strategy for realizing subtle atomic shifts in the vanadate perovskite YVO₃.

“The aim of our recent study was to gain a fundamental understanding of how the functional properties of a crystalline material change when it is grown as a thin film oriented on different facets of another crystal, while controlling parameters such as lattice and polarity.” “The discrepancy with film remains almost unchanged,” Eva Benckiser, lead author of the paper, told Phys.org.

In order to specifically imprint slight atomic displacements into the antiferromagnetic Mott insulator YVO₃the researchers deposited epitaxial films on different facets of the same substrate. In particular, they observed that the vanadate films on different facets of the substrate had different spin orbital ordering patterns.

“In materials with strong electron-electron correlations, such as the perovskite vanadate YVO₃“The physical properties react very sensitively to the smallest structural changes, such as those that occur at interfaces when materials with different crystal lattices grow together,” explains Benckiser.

“In the present work, we used two sections of an orthorhombic substrate material, YAlO₃whose facets are indistinguishable in the cubic reference system and which have a very similar lattice mismatch to YVO₃.”

The current study by Benckiser and her colleagues shows that substrate facets could be used to carefully tailor the spin-orbital behavior of perovskites. Initial experiments highlight the promise of their proposed approach, which could eventually be used to develop new materials for various technologies.

“Our light scattering experiments show that the magnetic ordering patterns differ depending on the substrate facet and that this is due to the subtle difference in atomic displacements imprinted at the substrate-film interface,” Benckiser said. “This fundamental effect can be used to stabilize desired phases in various functional perovskite materials, for example to create novel spintronic materials.”

The researchers hope their recent work will contribute to the precise engineering of quantum materials and provide physicists with an alternative way to manipulate their properties. In the meantime, they plan to further expand the approach they developed while also investigating the extent to which imprinted displacement patterns influence the properties of other perovskites.

“In the future, we plan to study the length scale of the imprinted orthorhombic shifts in more detail and investigate the influence of different facets in other functional perovskite thin films,” Benckiser added.

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