Spin Disorder and Particle Size Effects in Cobalt Ferrite Nanoparticles with Unidirectional Anisotropy and Permanent Magnet-like Characteristics

2020 ◽  
Vol 124 (47) ◽  
pp. 25992-26000
Author(s):  
Bharati Debnath ◽  
Hemant G. Salunke ◽  
Sayan Bhattacharyya
Keyword(s):  
Particle Size ◽  
Permanent Magnet ◽  
Size Effects ◽  
Cobalt Ferrite ◽  
Ferrite Nanoparticles ◽  
Particle Size Effects ◽  
Cobalt Ferrite Nanoparticles ◽  
Spin Disorder ◽  
Unidirectional Anisotropy

Cobalt ferrite nanoparticles: The control of the particle size and surface state and their effects on magnetic properties

2007 ◽  
Vol 311 (1) ◽  
pp. 10-16 ◽  
Author(s):  
Giovanni Baldi ◽  
Daniele Bonacchi ◽  
Claudia Innocenti ◽  
Giada Lorenzi ◽  
Claudio Sangregorio
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Surface State ◽  
Cobalt Ferrite ◽  
Ferrite Nanoparticles ◽  
Cobalt Ferrite Nanoparticles

A Statistical Analysis to Control the Growth of Cobalt Ferrite Nanoparticles Synthesized by the Thermodecomposition Method

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Victoria L. Calero-DdelC ◽  
Ana M. Gonzalez ◽  
Carlos Rinaldi
Keyword(s):  
Particle Size ◽  
Statistical Analysis ◽  
Growth Temperature ◽  
Cobalt Ferrite ◽  
Particle Diameter ◽  
Ferrite Nanoparticles ◽  
Nucleation Temperature ◽  
Growth Stages ◽  
Final Particle ◽  
Cobalt Ferrite Nanoparticles

A statistical design of experiments was used to study the effect of reaction temperature and time on the synthesis of cobalt ferrite nanoparticles by the thermodecomposition method. A 24–2 factorial experimental design with two central points was used in which the control variables were the time and temperature of the nucleation and growth stages. Transmission electron microscopy, X-ray diffraction, inductively coupled plasma optical emission spectroscopy, and magnetic measurements were used for particle characterization. Cobalt-substituted ferrite (CoxFe3−xO4) nanoparticles with diameters between 9 nm and 13 nm were obtained by varying the nucleation temperature between 150°C and 250°C, the growth temperature between 300°C and 330°C, and the time in each stage between 60 min and 120 min. Statistical analysis showed that only the temperatures had an influence on the final particle size. The analysis of variance indicates that increase in the nucleation temperature resulted in decreased particle size, whereas the increase in temperature in the growth stage resulted in an increase in particle size. Additionally, statistical analysis showed that the growth temperature had an effect on Fe/Co ratio. An increase in the growth temperature produces a decrease in the Fe/Co ratio. Finally, a statistically significant correlation was found between particle diameter and saturation magnetization at 5 K and 300 K. No correlation was found between diameter and other magnetic properties.

Exploring the Magnetic Properties of Cobalt-Ferrite Nanoparticles for the Development of a Rare-Earth-Free Permanent Magnet

2015 ◽  
Vol 27 (11) ◽  
pp. 4048-4056 ◽  
Author(s):  
Alberto López-Ortega ◽  
Elisabetta Lottini ◽  
César de Julián Fernández ◽  
Claudio Sangregorio
Keyword(s):  
Magnetic Properties ◽  
Rare Earth ◽  
Permanent Magnet ◽  
Cobalt Ferrite ◽  
Ferrite Nanoparticles ◽  
Cobalt Ferrite Nanoparticles
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