Synthesis and investigation of mixed Zn–Ni spinel nanoparticles for microwave applications

AbstractNickel ferrite solid solutions remain one of the main materials for a whole range of applications, including microwave equipment and components, the requirements for parameters and homogeneity of materials are constantly increasing. In this work, Ni1–xZnxFe2O4 nanoparticles with an average diameter of 12.5 nm were successfully synthesized by the microwave-assisted urea method. The temperature of a single-phase product formation was 400 °C, which is lower compared to more common precipitation from aqueous solution methods or solid-state route. Ni1–xZnxFe2O4 materials demonstrate high saturation magnetization and low coercive force. The magnetization changes with increasing Zn concentration and reaches the maximum at x = 0.5. Also, the increase in zinc content leads to an increase in the lattice parameters. The average size of ferrite nanoparticles synthesized by the microwave-assisted urea method is smaller compared to ferrites synthesized earlier by the co-precipitation method. Also, lower treatment temperatures provide higher stoichiometry, and homogeneity of materials while magnetization difference is negligible. These research results provide a general and effective route to synthesize other nanostructures for a variety of microwave components.Keywords: Lattice constantmagnetic propertiesNiFe2O4zinc substitutionZnFe2O4 AcknowledgmentsThe authors express their gratitude to the Armed Forces of Ukraine for providing security to perform this work. This work has become possible only because of the resilience and courage of the Ukrainian Army. The Czech Group acknowledges financial support from the project of the Ministry of Education, Youth and Sports (LM 2018116). The authors are grateful to the Center of Mossbauer Spectroscopy at G. V. Kurdyumov Institute for Metal Physics of the National Academy of Sciences of Ukraine.Disclosure statementThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article.Additional informationFundingThis work was supported in part by the NATO Science for Peace and Security Programme within the framework of the “3D Metamaterials for Energy Harvesting and Electromagnetic Sensing” project (ID SPS G6002).