First-principles studies of multiferroic and magnetoelectric materials

Multiferroics are materials where two or more ferroic orders coexist owing to the interplay between spin, charge, lattice and orbital degrees of freedom. The explosive expansion of multiferroics literature in recent years demon-strates the fast growing interest in this field. In these studies, the first-principles calculation has played a pioneer role in the experiment explanation, mechanism discovery and prediction of novel multiferroics or magnetoelectric materials. In this review, we discuss, by no means comprehensively, the extensive applications and successful achievements of first-principles approach in the study of multiferroicity, magnetoelectric effect and tunnel junc-tions. In particular, we introduce some our recently developed methods, e.g., the orbital selective external potential (OSEP) method, which prove to be powerful tools in the finding of mechanisms responsible for the intriguing phe-nomena occurred in multiferroics or magnetoelectric materials. We also summarize first-principles studies on three types of electric control of magnetism, which is the common goal of both spintronics and multiferroics. Our review offers in depth understanding on the origin of ferroelectricity in transition metal oxides, and the coexistence of fer-roelectricity and ordered magnetism, and might be helpful to explore novel multiferroic or magnetoelectric materi-als in the future.

💡 Research Summary

The review article provides a comprehensive overview of how first‑principles calculations, primarily based on density‑functional theory (DFT), have driven progress in the field of multiferroic and magnetoelectric materials. It begins by outlining the scientific appeal of multiferroics—materials that simultaneously exhibit two or more ferroic orders such as ferroelectricity (FE) and ferromagnetism (FM)—and highlights their relevance to spintronics, low‑power memory, sensors, and other emerging technologies. The authors argue that experimental discovery alone cannot keep pace with the rapid expansion of the literature, and that computational methods are essential for elucidating mechanisms, interpreting measurements, and predicting new compounds.

A central contribution of the paper is the introduction and systematic discussion of the Orbital‑Selective External Potential (OSEP) method, a customized approach that applies an artificial external potential to selected electronic orbitals (typically transition‑metal d states). By shifting the energy of a chosen orbital, OSEP directly controls its occupation, thereby allowing researchers to probe the causal link between orbital polarization, lattice distortions, spin‑orbit coupling, and exchange interactions. The authors demonstrate that OSEP can reveal subtle electronic‑lattice couplings that conventional DFT often misses, making it a powerful “virtual experiment” for dissecting the origin of coexisting ferroelectric and magnetic orders.

The review then categorizes electric‑field control of magnetism into three distinct mechanisms. (1) Structural control: an applied electric field modifies the ferroelectric lattice, which in turn changes super‑exchange pathways and magnetic ordering. (2) Electronic control: the field directly perturbs the electronic band structure, altering orbital occupations and spin‑orbit interactions, leading to a change in magnetic anisotropy or even a reversal of spin orientation. (3) Interfacial charge control: at heterointerfaces, the electric field redistributes charge carriers, thereby modulating the interfacial exchange bias and spin polarization. For each mechanism, the authors present quantitative DFT‑based results—energy barriers, critical field strengths, temperature dependencies—and compare them with experimental observations, showing good agreement.

In addition to bulk phenomena, the paper examines magnetoelectric tunnel junctions (METJs), where a ferroelectric barrier separates non‑magnetic electrodes. First‑principles transport calculations reveal that the ferroelectric polarization state strongly influences spin‑polarized tunneling currents, enabling electric‑field‑driven switching of the spin polarization. This dual functionality—simultaneous control of charge and spin transport—positions METJs as a promising platform for next‑generation spintronic devices.

The authors conclude by outlining future directions. They advocate for the integration of high‑throughput DFT screening with machine‑learning models to accelerate the discovery of novel multiferroic compounds. They also suggest extending OSEP to time‑dependent and non‑equilibrium frameworks to capture real‑time dynamics under pulsed electric fields. Finally, they emphasize the need for multiscale modeling that bridges atomistic first‑principles insights with mesoscopic device simulations, thereby translating fundamental discoveries into practical technologies. Overall, the review convincingly demonstrates that first‑principles calculations are not merely supportive tools but are central to understanding, designing, and engineering multiferroic and magnetoelectric materials for future applications.