Preparation and Characterization of Copper Chromium Oxide Nanoparticles Using Modified Sol‐Gel Route and Evaluation of Their Microwave Absorption Properties

In this study, simple, broadband, robust, and affordable microwave absorbing nanocomposites are prepared using CuCr 2 O 4 nanoparticles as guests and silicone rubber or poly(vinylidene fluoride) (PVDF) as host. Firstly, the pristine and modified CuCr 2 O 4 nanoparticles are obtained by the conventional citrate gel method in the absence and presence of sucrose as a novel capping agent in the experimental steps. X‐ray powder diffraction (XRD) patterns confirms that the CuCr 2 O 4 nanoparticles are synthesized. Moreover, morphologies, chemical functional groups, and optical properties are studied using field emission scanning electron microscopy (FE‐SEM), Fourier transform infrared (FT‐IR), and diffuse reflection spectroscopy (DRS), respectively. The vibrating sample magnetometer (VSM) analysis reveals weak magnetic properties for the nanoparticles and confirms that the capping agent change the magnetic properties. Finally, bare and modified copper chromium oxide nanoparticles are separately molded with silicone rubber or PVDF to compare dipole and interfacial polarization. Besides, using a vector network analyzer (VNA) along the x and ku‐band frequency, novel organic precursor effects on their microwave absorption properties are examined. According to the obtained results, the maximum reflection loss of the modified CuCr 2 O 4 /PVDF is −65.57 dB at 14 GHz with 2 mm thickness and the CuCr 2 O 4 /PVDF nanocomposite absorbs a bandwidth of 7.73 GHz more than 10 dB with a thickness of 2 mm. Interestingly, novel one type filler lead to significant microwave absorbing properties as well as organic capping agent reinforced maximum microwave absorption also PVDF improves absorption bandwidth.