In recent years, multifunctional multiferroics, which have two or more ferroic properties (such as ferroelectricity, (anti)ferromagnetism, or ferroelasticity), have generated increasing levels of interest in the world of novel multifunctional materials, due to the possibility of controlling magnetic order with an electric field, and vice-versa. Due to the interaction between spin and charge, the coexistence of ferroelectricity and ferromagnetism has the potential to exhibit magnetoelectric effects. Magnetoelectric effects on multiferroics are expected to have great impact on the production of future advanced devices.

Developing novel multifunctional materials and exploring their applicability has become the focus of increasing amounts of research across an increasingly wide range of fields, including the development of materials, sensors, and actuators, and for biomedical applications. Although the research community has made positive progress in these areas, it is still necessary to discuss the main problems that should be solved for practical applications, such as performance improvement, in-depth understanding of the physical and chemical properties of the materials, processability, equipment integration, and reliability. It seems worth noting that open questions, problems, and challenges are continuously emerging, providing a source of future research ideas and applications.

The aim of this Special Issue is to fundamentally understand magnetoelectric multiferroic materials and summarise their recent developments in single-phase and composite multiferroic materials (bulk, nano, and thin films), focusing on their synthesis, structure–property relations, and their applications in novel device architectures.

Potential topics include but are not limited to the following:

• Multiferroic materials
• Composite multiferroics
• Single-phase multiferroics
• Functional nanomaterials
• Magnetoelectric coupling
• Multifunctional nanostructures for sensor applications
• Spintronic applications
• Design, fabrication processes, and synthesis of multiferroic nanomaterials
• Device design based on multiferroic nanomaterials
• Synthesis of multiferroic materials
• Structural properties of multiferroics
• Magnetisation, ferroelectric, and magnetoelectric switching and dynamics