Soft magnetic materials have been continuously evolving since the nineteenth century, a time that brought major breakthroughs in electromagnetism. In 1820, Hans Christian Ørsted demonstrated that a wire carrying an electrical current behaved like a magnet. Just four years later, William Sturgeon discovered that by wrapping the wire around a piece of iron, the magnetic field became more powerful. This was the invention of the first electromagnet. Then, in 1831, Michael Faraday wound two coils around a ring of iron and discovered electromagnetic induction. During the early 1900s, soft magnets moved rapidly from iron to new materials with the development of novel alloys and manufacturing approaches. These advances led to prominent and practical applications, such as electric motors, generators, and transformers. Today, research on soft magnetic materials continues to be active and vibrant as they remain key components in the conversion, storage, and distribution of both energy and information.

A push for greater efficiency and decreased size in power electronics and electrical machines (motors and generators) demands higher performing soft magnetic materials. To be competitive, advanced soft magnetic materials must be affordable, and their production volume needs to meet the anticipated demand. This drive for higher efficiency and diminished size, weight, and power (SWaP) is fueled in part by the development and adoption of wide band gap (WBG) semiconductors. WBG devices enable very fast switching (1 kHz to as high as 10 MHz), high voltage operation, and high temperature operation in both power electronics and electrical machine drives. Researchers in the field of soft magnetics must rise to this challenge and create materials with high saturation magnetizations and low electrical losses. The magnetics community also needs to improve the theoretical assessment of magnetic behavior and energy losses at elevated switching frequencies. Convergence of fundamental and applied investigations have been a key to exciting developments in many fields and can also be fruitful for soft magnetic materials, particularly as the pace of research is increased.

This Focus Issue brings together the latest research on soft magnetic materials for next-generation electromagnetic devices, from power electronics, to transformers, to magnetomechanical sensors and magnetic refrigeration. Additionally, the entire materials science paradigm (processing, structure, properties, and performance) are covered within this issue. Advanced synthesis and characterization techniques are vital to understanding both the nanostructure and dynamical properties in soft magnetic materials. The behavior of soft magnets on small length and short time scales will ultimately govern their performance in electromagnetic devices, while analytical and numerical modeling will serve as tools for analyzing and optimizing device design. This issue aims to be an inspiration to both the current and next generation of soft magnetic material scientists.