Cation distribution in CuFe{sub 2}O{sub 4} nanoparticles: Effects of Ni doping on magnetic properties

• Published in: Journal of applied physics 2016-10, Vol.120 (14)
• Main Authors: Thanh, Nguyen Kim, Loan, To Thanh, Anh, Luong Ngoc, Duong, Nguyen Phuc, Hien, Than Duc, Soontaranon, Siriwat, Thammajak, Nirawat
• Format: Article
• Language: English
• Subjects: ABSORPTION; ABSORPTION SPECTROSCOPY; CATIONS; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COPPER IONS; COPRECIPITATION; CRYSTAL STRUCTURE; CURIE POINT; DISTRIBUTION; GRAIN SIZE; IRON IONS; LATTICE PARAMETERS; MAGNETIC PROPERTIES; MATERIALS SCIENCE; NANOPARTICLES; NICKEL IONS; SCANNING ELECTRON MICROSCOPY; SYNCHROTRONS; VIBRATING SAMPLE MAGNETOMETERS; X RADIATION; X-RAY DIFFRACTION; X-RAY SPECTROSCOPY
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4961722

The Cu{sub 1−x}Ni{sub x}Fe{sub 2}O{sub 4} nanoparticles (with x = 0, 0.3, 0.5, 0.7, and 1) were synthesized by using spray co-precipitation method at annealing temperature T{sub a} = 900 °C in air for 5 h. The crystal structure, microstructure, oxidation state, and magnetic properties of the samples were characterized by using X-ray diffraction, synchrotron X-ray diffraction, scanning electron microscopy, X-ray absorption spectroscopy, and vibrating sample magnetometer. It was shown that all the samples have cubic structure. Lattice constant and grain size decrease, while the Curie temperature T{sub C} increases with increasing of Ni{sup 2+} content. A small amount of Fe{sup 2+} was found in all the samples. Cation distribution was determined by using a combination of magnetization measurements, extended X-ray absorption fine structure analysis, and Rietveld refinement from synchrotron X-ray diffraction data. It was indicated that Ni{sup 2+} ions occupy in octahedral site only, while Cu{sup 2+} ions distribute in both tetrahedral and octahedral sites. The variation of magnetic parameters is discussed based on Ni{sup 2+} concentration, grain size, the cation distribution, surface effect, and the presence of Fe{sup 2+} ion in the samples.