Amid the rapid evolution of next-generation power systems, energy storage, and the new‑energy industry, solid‑state transformers (SSTs), with their advantages of high controllability, compact size, and high power density, have emerged as core components of smart grids. Meanwhile, high‑frequency magnetic core materials are pivotal in determining SST efficiency, Key to volume, temperature rise, and reliability.

The microstructural differences between the two magnetic core materials give rise to markedly distinct electrical, mechanical, and thermal properties:

Manganese-zinc ferrite : Ceramic sintered crystalline materials exhibit extremely high resistivity, boast mature manufacturing processes and diverse form factors, and are the standard material for conventional high-frequency switching power supplies, emphasizing excellent cost‑performance.

Iron-based nanocrystalline : Formed through secondary heat treatment of amorphous materials, it features a dual-phase microstructure consisting of an amorphous matrix and nanocrystalline grains, offering low losses, broad temperature stability, and high permeability, making it widely used in high-end power‑equipment applications.

The higher the magnetic flux density, the smaller the core volume at the same power level, and the greater the device’s power density. The saturation magnetic flux density of iron-based nanocrystalline materials can reach 1.2–1.3 T. It boasts excellent magnetic flux‑carrying capability, enabling significant reduction in core volume and markedly increasing the power density of the device. Manganese‑zinc ferrites, with a saturation magnetic induction of only 0.4–0.6 T, have relatively limited flux‑handling capacity, which can constrain device integration and lead to bulky designs, making them suitable primarily for low‑to‑medium‑power, lightweight applications.

Loss characteristics directly determine equipment energy efficiency and thermal management challenges, serving as the fundamental basis for the division of roles between the two materials. Under medium-frequency (1–40 kHz) high-power operating conditions, typical iron losses range from 5 to 20 W/kg, enabling transformer‑level efficiencies exceeding 99% and delivering significant energy‑saving benefits.

Ferrite boasts high resistivity and extremely low eddy‑current losses, delivering excellent performance in ultra‑high‑frequency, low‑power applications above 50 kHz. However, at medium frequencies and under high power conditions, its losses become relatively high, leading to significant heating. Iron‑based nanocrystalline materials, by contrast, are broadband‑optimized composites that exhibit markedly lower losses than ferrites in the 20–100 kHz mid‑to‑high frequency range, with superior temperature‑rise control and low operating noise, making them well suited for complex operating scenarios involving wide bandwidths, high power levels, and heavy loads.

The initial permeability of nanocrystalline materials can reach 80,000 to 100,000, offering distinct advantages: low excitation loss and precise switching response, making it well-suited for… Compatible with high precision and stringent requirements Electrical equipment. Ferrite permeability ranges from 1,500 to 15,000, with stable high-frequency response. The performance parameters are well balanced, meeting the basic operational requirements of standard high-frequency power supply equipment. 。

Temperature stability is a critical enabler of the long-term reliable operation of power equipment. The Curie temperature of iron‑based nanocrystalline materials is 560–570 °C, with a maximum continuous operating temperature of up to 180 °C. Within this broad temperature range, their magnetic properties exhibit minimal variation, making them well suited for harsh high‑temperature conditions such as outdoor exposure and poorly ventilated enclosed cavities. In contrast, manganese‑zinc ferrites have a much lower Curie temperature of only 180–220 °C; however, due to material‑specific limitations, their maximum continuous operating temperature is limited to ≤100 °C. Under elevated temperatures, core losses rise sharply, reliability deteriorates, and their application scope becomes significantly constrained.

Ferrite is a ceramic material that is highly brittle and prone to cracking; however, its forming processes are well‑established, enabling the fabrication of complex geometries such as E‑shaped and toroidal cores, with a high degree of standardization. Nanocrystalline materials, on the other hand, rely on precision thin‑strip heat‑treatment processes, which demand stringent machining accuracy and impose limitations on strip dimensions, making it difficult to produce ultra‑large‑capacity magnetic cores. Consequently, mass‑production costs remain relatively high, and scrap rates tend to be elevated.

Single-purchase cost: Manganese–zinc ferrite boasts a mature manufacturing process and low production costs, offering a significant cost‑performance advantage. In contrast, iron‑based nanocrystalline materials and their processing are more expensive, resulting in higher upfront capital expenditures. From a full‑life‑cycle cost‑effectiveness perspective, in small‑ to medium‑power civilian applications, manganese–zinc ferrite adequately meets operational requirements while delivering the best cost‑control outcomes. For high‑end, demanding operating conditions, iron‑based nanocrystalline materials, with their core attributes of low loss, high stability, and long service life, can effectively reduce equipment cooling energy consumption as well as operation, maintenance, and replacement costs, yielding superior long‑term overall cost‑effectiveness.

Medium- and low-power, ultra‑high‑frequency consumer devices: manganese‑zinc ferrites are preferred. They are well suited for residential energy storage and small switching power supplies, offering low cost and mature manufacturing processes that meet everyday operating requirements.

Mid-to-high frequency, high-reliability, high-end equipment: prioritizes iron-based nanocrystalline materials. Suitable for automotive SSTs, precision power‑electronics devices, and outdoor grid‑connected equipment, offering excellent resistance to extreme temperatures, low noise, and stable performance, while meeting the demands of harsh operating conditions.

There is no absolute “optimal solution” for magnetic cores; there are only… Choosing the Most Suitable Scenario In practical design, only by comprehensively evaluating four key factors—device operating frequency, power rating, operating environment, and cost constraints—can the performance of magnetic core materials be optimized, enabling the development of solid-state transformers that are efficient, stable, and highly cost‑effective.