Defect-engineering-driven synergistic modulation of dual-phase (Fe₀.₅Mg₀.₅CoNiCuMn)₃O₄@CuO ceramics for superior microwave absorption

To address the growing problem of electromagnetic pollution, the development of high-performance wave-absorbing materials is critical. High-entropy ferrites demonstrate significant advantages by synergistically regulating dielectric and magnetic losses through their multi-element magnetic ions and disordered cation distributions. However, their performance in single-phase form is limited by the difficulty in achieving an ideal match between electrical conductivity and permittivity. Consequently, constructing multiphase composite structures and implementing precise defect engineering emerge as key strategies. In this work, based on defect-engineering-driven synergistic modulation, composite ceramics of high-entropy ferrite ((Fe₀.₅Mg₀.₅CoNiCuMn)₃O₄) and copper oxide (CuO) are successfully fabricated, achieving the controllable construction of defect gradient.

Recently, a team of material scientists led by Lixi Wang from Nanjing Tech University, China first reported the

composition, structure, morphology, defect engineering design, microwave absorption properties, mechanism of enhanced electromagnetic wave absorption and thermal transport properties of (Fe₀.₅Mg₀.₅CoNiCuMn)₃O₄)@CuO. This work not only regulated the oxygen vacancy concentration and the degree of lattice distortion, but also achieved excellent electromagnetic wave absorption properties.

The team published their work in Journal of Advanced Ceramics on December 10, 2025.

“In this report, we synthesized (Fe₀.₅Mg₀.₅CoNiCuMn)₃O₄@CuO composite ceramics with tunable microwave absorption. The lattice distortion and surface oxygen vacancy concentration were positively correlated with absorption performance. The optimized material exhibited a minimum reflection loss of –48 dB and an effective absorption bandwidth of 3.9 GHz in the X-band, attributed to the frequency-dependent synergistic effect between dielectric and magnetic loss mechanisms” said Lixi Wang, professor at Nanjing Tech University (China), a senior expert whose research interests focus on the field of wave-absorbing materials and spectral conversion materials.

“We find that both lattice distortion and surface oxygen vacancy concentration follow a parabolic trend, first rising and then falling—a pattern mirrored in the reflection loss and absorption bandwidth. This synergy stems from a balanced defect effect: moderate distortion enhances polarization loss by creating metal vacancies and strengthening dipoles, while excessive distortion causes elemental segregation and disrupts conduction. Similarly, optimal oxygen vacancies lower the electron transition barrier and act as polarization centers, boosting dielectric loss; too many, however, overload the lattice, degrading its integrity and loss performance.” said Lixi Wang.

“The material developed in this study demonstrates unique comprehensive advantages. Its thermal conductivity of 2.154 W·m⁻¹·K⁻¹ not only far exceeds that of traditional wave-absorbing fillers but also, through defect engineering and dual-phase regulation, equips it with considerable electromagnetic wave dissipation capability.” said Lixi Wang.

However, more refined research efforts are still required to explore the applicability of high-entropy ceramics as wave-absorbing materials. In this regard, Wang further proposed five main future research directions that could be pursued, including: (1) the establishment of multi-scale structure–property relationship models; (2) precise doping and gradient structure design to tailor electromagnetic parameters; (3) integration of multiple loss mechanisms via multiphase/heterointerface engineering; (4) performance optimization under extreme environments such as high temperature and oxidation; and (5) the development of smart or self-healing wave-absorbing materials

Other contributors include Xia Feng, Yixiang Lu, Fanqi Meng, Yi Hou, Xiaodong Feng, Haikui Zhu from the Nanjing Tech University, China.

This work was supported by National Natural Science Foundation of China (General Program 12374394；Youth Project 52402362)，Youth Project of Natural Science Foundation of Jiangsu Province (BK20230341), Nanjing Overseas Educated Personnel Science and Technology Innovation Program, "Qinglan Project" Young, Middle-aged Academic Leaders Program of Jiangsu Province and Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).

About Author

Wang Lixi, Professor, specializing in wave-absorbing materials and spectral conversion materials. She was recognized as a "Young and Middle-aged Academic Leader" under the Qinglan Project in 2021, named a Global "Top 1% Highly Cited Author" by the Royal Society of Chemistry in 2019, and honored as an Outstanding Expert in the Suqian Dual Hundred Talents Project. She also serves as a Council Member of the Youth Working Committee of the Chinese Materials Research Society and a Council Member of the Jiangsu Society of Composite Materials. Her awards include the Third Prize for Technological Invention (ranked second) from the China Petroleum and Chemical Industry Federation and the Second Prize for Scientific and Technological Progress (ranked second) from the Jiangsu Society of Composite Materials. She has led eight national-level projects and two provincial-level projects, published over 100 SCI/CSSCI-indexed papers, and filed more than twenty patent applications.

About Journal of Advanced Ceramics

Journal of Advanced Ceramics (JAC) is an international academic journal that presents the state-of-the-art results of theoretical and experimental studies on the processing, structure, and properties of advanced ceramics and ceramic-based composites. JAC is Fully Open Access, monthly published by Tsinghua University Press, and exclusively available via SciOpen. JAC’s 2024 IF is 16.6, ranking in Top 1 (1/33, Q1) among all journals in “Materials Science, Ceramics” category, and its 2024 CiteScore is 25.9 (5/130) in Scopus database. ResearchGate homepage: https://www.researchgate.net/journal/Journal-of-Advanced-Ceramics-2227-8508