Sintering behaviour of cobalt ferrite ceramic

Abstract

Pure cobalt ferrite ceramic powder was prepared using standard solid-state ceramic processing. Uniaxially pressed pure cobalt ferrite discs, sintered under isothermal ramp rate and single dwell time conditions, yielded a maximum theoretical density (%Dth) of <90%. Discs made from finer particle size powder yielded a %Dth of 91.5%. Based on dilatometry analysis, a sintering profile comprising non-isothermal sintering, and two-step sintering was devised, yielding discs with %Dth of 96%. Cylindrical rods of pure cobalt ferrite were cold iso-statically pressed and sintered according to the revised sintering profile. Pycnometry analysis was used to quantify the percentages of open and closed pores in the rods after sintering.

Synthesis and characterization of cobalt ferrites nanoparticles with cytotoxic and antimicrobial properties

“…The antimicrobial activities of magnetic nanoparticles are well established by Chifiriuc et al (2011). Cobalt ferrites nanoparticles were synthesized using different techniques such as solid state reaction (Rafferty et al, 2008) microemulsion (Choi, 2003), combustion (Yan, 1999) the redox process (Rajendran, 2001), chemical co-precipitation (Pannaparayil and Komarneni, 1989), the hydrothermal method (Daou, 2006), and microwave synthesis (Bensebaa, 2004). Generally, the evaluation of magnetic nanoparticles for drug delivery, and sensing applications are widely studied.…”

Crystallographic and magnetic identification of secondary phase in orientated Bi5Fe0.5Co0.5Ti3O15 ceramics

“…It has previously been reported that a Co and Fe rich phase may be formed at high temperature. 10 Consequently, there is more possibility for the Co and Fe rich secondary phase to form in the molten salt method due to the higher sintering temperature, 1000 C, in comparison with conventional method which was only 850 C. Consequently, more secondary phase exists in BFCT prepared by the molten salt method which results in the ceramic having a higher remanent magnetization.…”

Crystallographic and magnetic identification of secondary phase in orientated Bi<inf>5</inf>Fe<inf>0.5</inf>Co<inf>0.5</inf>Ti<inf>3</inf>O<inf>15</inf> ceramics

“…It has previously been reported that a Co and Fe rich phase may be formed at high temperature. 10 Consequently, there is more possibility for the Co and Fe rich secondary phase to form in the molten salt method due to the higher sintering temperature, 1000 C, in comparison with conventional method which was only 850 C. Consequently, more secondary phase exists in BFCT prepared by the molten salt method which results in the ceramic having a higher remanent magnetization. Based on TEM electron diffraction pattern and EDX chemical data, it can be concluded that the secondary phase is rich in Co and Fe.…”