Effect of Cetyl trimethylammonium bromide (CTAB) amount on phase constituents and magnetic properties of nano-sized NiFe sub(2)O sub(4) powders synthesized by sol-gel auto-combustion method

• Published in: Journal of alloys and compounds Vol. 638; pp. 121 - 126
• Main Authors: Alamolhoda, S, Mirkazemi, S M, Shahjooyi, T, Benvidi, N
• Format: Journal Article
• Language: English
• Published: 25.07.2015
• Subjects: Combustion products; Constituents; Magnetic properties; Mathematical analysis; Nanostructure; Raman spectroscopy; Sol gel process; X-ray diffraction
• ISSN: 0925-8388
• DOI: 10.1016/j.jallcom.2015.02.192

In this research nano-sized NiFe sub(2)O sub(4) powders were synthesized with and without Cetyl trimethylammonium bromide (CTAB) surfactant addition by sol-gel auto-combustion method. Phase constituents, microstructure and magnetic properties as a result of different CTAB addition amounts were evaluated by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscope (FESEM) and vibration sample magnetometer (VSM) techniques. XRD results designated that the combustion product consists of NiFe sub(2)O sub(4) as the main phase and some amount of alpha -Fe sub(2)O sub(3) and FeNi sub(3) phases. Raman spectroscopy represents the formation of NiO phase in addition to the mentioned phases. CTAB addition affects the phase constituents and elimination of alpha -Fe sub(2)O sub(3) residuals from the combustion product while facilitating the formation of FeNi sub(3) phase. Also its addition leads to powder refinement based on FESEM images. Mean crystallite sizes of the samples by calculated by Scherrer equation showed a decreasing trend from 46 to 27 nm with increasing the amount of CTAB. Magnetic measurements showed that saturation magnetization increased from 36.96 emu/g to 51.07 emu/g by CTAB addition as a result of increased FeNi sub(3) amount. The intrinsic coercivity values ( sub(i)H sub(c)) of the samples are in the range of 164-175 Oe.