The effects of calcination atmosphere and Fe3+ content on NiFexAl2-xO4 nano pigments synthesized via a polyacrylamide gel method
- 1 Department of Materials Engineering, Naghshejahan Institute of Higher Education, Baharestan, Isfahan, Iran
- 2 Department of Materials Science and Engineering, Shahreza Branch, Islamic Azad University, Shahreza, Iran
Abstract
In this research, NiFexAl2-xO4 pigments (x=0, 0.3, 0.7, and 1.5) were synthesized using a polyacrylamide gel method and the effects of calcination atmosphere and the dopant amount on the formed phases and optical properties were investigated. The physical, optical, and microstructural properties of the obtained pigments were clarified using the XRD, UV-Vis spectroscopy, and FESEM techniques. The phase analysis showed that the nickel carbide was formed in the reducing atmosphere instead of the spinel phase. So, the rest of the samples were prepared in an oxidizing atmosphere. The obtained pigments had a spherical morphology and a narrow particle size distribution due to the growth inhibitor role of the polyacrylamide network. The iron ions entered both tetrahedral and octahedral sites of the nickel aluminate structure, acted as the main chromophore, and turned the color from cyan to brown. Further addition of iron led to the darkening of the brown color.
Downloads
Copyright (c) 2025 Rayehe Tavakolipour

This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright
Authors are the copyright holders of their published papers in Synthesis and Sintering, which are simultaneously licensed under a Creative Commons Attribution 4.0 International License. The full details of the license are available at https://creativecommons.org/licenses/by/4.0/.
All papers published open access will be immediately and permanently free for everyone to read, download, copy, distribute, print, search, link to the full-text of papers, crawl them for indexing, pass them as data to software, or use them for any other lawful purpose without any registration obstacles or subscription fees.