A novel (La0.2Sm0.2Eu0.2Gd0.2Tm0.2)2Zr2O7 high-entropy ceramic nanofiber with excellent thermal stability

The microstructure of ceramic fibers is destroyed, as a result of phase transformation and fiber diameter growth. In this work, (La 0.2 Sm 0.2 Eu 0.2 Gd 0.2 Tm 0.2 ) 2 Zr 2 O 7 high-entropy ceramic nanofibers (HE-RE 2 Zr 2 O 7 fibers) were prepared by the electrospinning method for the first time. XRD and TEM analyses indicated that the HE-RE 2 Zr 2 O 7 fibers existed as a pure phase with a uniform distribution of rare-earth elements. SEM images showed that the HE-RE 2 Zr 2 O 7 fibers retained a dense structure up to 1000 °C for 0 h–5 h. Upon annealing at 1000 °C for 0 h–2.5 h, the mean diameter of the HE-RE 2 Zr 2 O 7 fibers increased from 169.34 nm to 176.95 nm, and the mean diameter of the La 2 Zr 2 O 7 fibers increased from 174.52 nm to 215.14 nm. The thermal conductivity of the HE-RE 2 Zr 2 O 7 fibers was approximately 0.23 W m −1 K −1 . The sluggish diffusion effect of high-entropy materials and the slow fiber diameter growth and excellent thermal stability of the HE-RE 2 Zr 2 O 7 fibers promote the broad application of these fibers as high-temperature heat insulation materials.