Neat and precise tuning of electronic structures with versatile strain engineering

Precise tuning of the localized electronic structure in transition metal oxides is key to advancing functional materials, yet conventional chemical methods often introduce un-neat side effects that impede control and complicate mechanistic studies. We propose a neat strategy that uses facile and versatile quenching-induced lattice tensile strain to adjust d-p orbital hybridization in metal-oxygen (M-O) bonds. Studies show that tensile strain boosts Mn 3d and O 2p orbital overlap, lowers Mn 3d energy levels, and enhances their splitting, increasing electron displacement-induced polarization loss. This significantly improves the microwave absorption of oxides, a top candidate for microwave absorbents currently limited by poor absorption performance. The strain-modified Mn_2.05Co_0.91O₄ achieves superior performance: a 7.52 GHz bandwidth (1.93 times that of zero-strain) and a minimum reflection loss of -67.47 dB. This approach's versatility is confirmed in perovskites, where strained samples exhibit 1.83 times the bandwidth of unstrained ones. This study connects lattice strain to electronic structure modulation for microwave absorbers, spintronics, catalysis, and semiconductors.