Defect Dipole-Induced HfO<sub>2</sub>-Coated Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub> MXene/Nickel Ferrite Nanocomposites for Enhanced Microwave Absorption
Salim Hassan Siddiki, Kartikey Verma, B. Chakraborty, Sushrut Das, Vijay Kumar Thakur, Ganesh Chandra Nayak
Abstract
This work reports for the first time the synthesis of a HfO 2 -coated Ti 3 C 2 T x MXene sandwich-like nanostructure (MXHf) using a simple hydrothermal method and their excellent microwave absorption property in combination with nickel ferrite and epoxy matrix. The nanocomposites of 2, 3, and 4 mm thick samples were tested for microwave absorption in the X-band, and a minimum reflection loss (RL min ) of −20.9 dB with EAB (effective absorption bandwidth) of 2.32 GHz was achieved for the 3 mm thick sample. Its superior performance results from the strong dielectric polarization of defect dipole in the MXene structure, the high number of oxygen vacancies brought about by HfO 2 nanoparticles, rich micro-interfaces in the sandwich-like HfO 2 -Ti 3 C 2 T x -HfO 2 structure, and impedance matching by NiFe 2 O 4 . A probable mechanism of absorption is proposed. Hence, HfO 2 /Ti 3 C 2 T x /NiFe 2 O 4 nanocomposites possess essential properties for real-time application in the defense and telecommunication industries.