Engineering of Ferroic Orders in Thin Films by Anionic Substitution

Abstract

Multiferroics are a unique class of materials where magnetic and ferroelectric orders coexist. The research on multiferroics contributes significantly to the fundamental understanding of the strong correlations between different material degrees of freedom and provides an energy‐efficient route toward the electrical control of magnetism. While multiple ABO3 oxide perovskites are identified as being multiferroic, their magnetoelectric coupling strength is often weak, necessitating the material search in different compounds. Here, the observation of room‐temperature multiferroic orders in multi‐anion SrNbO3−xNx thin films is reported. In these samples, the multi‐anion state enables the room‐temperature ferromagnetic ordering of the Nb d‐electrons. Simultaneously, ferroelectric responses that originate from the structural symmetry breaking associated are found with both the off‐center displacements of Nb and the geometric displacements of Sr, depending on the relative O‐N arrangements within the Nb‐centered octahedra. The findings not only diversify the available multiferroic material pool but also demonstrate a new multiferroism design strategy via multi‐anion engineering.

High Mobility Two-Dimensional Electron Gas at the BaSnO3/SrNbO3 Interface

“…With these Hubbard-U parameters, we obtained an equilibrium lattice parameter for cubic BSO, a = 4.118 Å (SNO: 4.044 Å), comparable to our DFT relaxed lattice parameter of 4.178 Å (SNO: 4.061 Å), and in excellent agreement with the experiment, 4.115 Å (SNO: 4.020 Å). The BSO band gap increases from 0.4 eV (DFT) to 3.6 eV (ACBN0), closer to the experimental band gap of 3.1 eV, while SNO remains non-magnetic metal, consistent with previous theory and experiment . We built different (BSO) N /(SNO) M heterostructures ( N , M refer to the number of cubic unit cells in each stack): (BSO)­4/(SNO)­2, (BSO)­4/(SNO)­4, (BSO)­6/(SNO)­6, (BSO)­7/(SNO)­7, and (BSO)­8/(SNO)­8.…”

Lattice dynamics across the ferroelastic phase transition in Ba2ZnTeO6: a Raman and first-principles study

“…8(a). This procedure is well-known to explain the source of the displacive phase transitions as in the case of ferroelectric perovskite oxide BaTiO 3 , 67 the strain-induced multiferroic state in the NaMnF 3 fluoride, 68,69 and the polar response in the Sr(Nb,Ta)O 2 N 70,71 oxynitrides. Fig.…”

Out-of-plane ferroelectricity and robust magnetoelectricity in quasi-two-dimensional materials

“…Multiferroics have been intensively studied since the discovery of room-temperature multiferroic BiFeO 3 ( 53 ) and type II multiferroic TbMnO 3 ( 54 ). Nowadays, electric-field control of magnetism has become a key to realize ultralow-power logic memory devices in recently developed device architectures ( 55 , 56 ). One priority for the scientific community is to broaden the set of materials that exhibit multiferroic and ME behavior at room temperature.…”