Tuning the structure of lychee-like LaFeO₃ for adjusting infrared stealth properties

The design and synthesis of perovskite-type oxide materials with precisely controlled morphology, crystal phase, and particle size are crucial yet challenging aspects in achieving low emissivity for high-temperature infrared stealth applications. A novel lychee-like LaFeO₃ (L-LFO) material was developed through a double-template-assisted hydrothermal method, given the significant impact of these structural parameters on infrared stealth performance. This strategy enables precise control over the material structure: the crystal phase was selectively stabilized to yield pure cubic perovskite LaFeO₃, the morphology was engineered into a distinctive lychee-like architecture via template-directed growth, and the particle size was confined to a narrow distribution ranging from 1 to 1.85 μm by optimizing the reaction time based on Mie scattering theory. The growth mechanism was systematically analyzed by varying the reaction time and template ratio. Comprehensive characterization employing SEM, TEM, XRD, XPS, and BET techniques confirmed the successful integration and control of morphology, crystal structure, and particle size. The results indicate that the L-LFO material synthesized under the optimal template molar ratio (5:2) exhibits remarkably low emissivity (ε_3∼5μm = ∼0.075 at 600 °C), surpassing the performance of existing perovskite materials and underscoring its substantial potential for high-temperature infrared stealth applications.