Construction of single-crystal nanoparticles assembled CuFe2O4 spinel microspheres towards high infrared emissivity

• Published in: Journal of alloys and compounds 2022-12, Vol.929, p.167365, Article 167365
• Main Authors: Cui, Kai, Sun, Minghui, Gong, Tianyu, Xu, Jiali, Hou, Linrui, Yuan, Changzhou
• Format: Article
• Language: English
• Subjects: Crystal structure; Emissivity; Heat treatment; High infrared emissivity; Infrared absorption; Infrared radiation; Low sintering temperatures; Microspheres; Nanoparticles; Room temperature; Single crystals; Single-crystalline subunits; Spherical spinels; Spinel; Temperature; Tetragonal CuFe2O4
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.167365

Recently, spinel-based materials have attracted tremendous interest in high infrared radiation regimes owing to their unique crystal structure. Nevertheless, to date, it still remains a formidable challenge to efficiently design and synthesize spinel materials with excellent infrared radiation properties at lower temperatures, especially for the tetragonal CuFe2O4 spinel. Herein, a simple two-step strategy (i.e., solvent-thermal treatment and subsequent calcination) was developed to fabricate single-crystalline nanoparticles assembled tetragonal CuFe2O4 microspheres (MSs) at a low sintering temperature of 800 °C (denoted as CFO-800). Thanks to the synergy of intrinsic factors including the single crystal properties and moderate CuO impurity as well as the unique spherical structure, the resultant CFO-800 specimen is endowed with enhanced infrared absorption. Consequently, the emissivity values are achieved as high as 0.514 at room temperature and even 0.972 at a test temperature of 800 °C in the wavelength range of 3 – 5 µm. More importantly, this research provides valuable insights into the rational design and construction of single-crystalline spinel materials with enhanced infrared radiation performance. [Display omitted] •Tetragonal CuFe2O4 microspheres are fabricated at a low annealing temperature of 800 ºC.•The unique spherical microstructure of CuFe2O4 enhances the infrared emission behavior by reducing the reflectivity.•Single-crystal nanoparticles assembled CuFe2O4 increases carrier concentration, favoring higher emissivity.•Moderate impurity phase CuO leads to lattice strain and oxygen vacancies, improving the infrared emissivity.•The infrared emission values of CuFe2O4 in the wavelength range of 3 – 5 µm are as high as 0.972.