Synthesis of single-phase cobalt ferrite nanoparticles via a novel EDTA/EG precursor-based route and their magnetic properties

Oxidation of o‐phenylenediamine to 2,3‐diaminophenazine in the presence of cubic ferrites MFe2O4 (M = Mn, Co, Ni, Zn) and the application in colorimetric detection of H2O2

“…The band (υ 2 ) with lower wave number, which is observed from 385 cm −1 to 450 cm −1 , corresponds to the octahedral−metal stretching vibrations . However, some researchers consider the presence of an intense band at about 550 cm −1 to be sufficient proof for the formation of the spinel structure . The typical FT–IR measurements for the prepared MFe 2 O 4 nanoparticles (M = Mn, Co, Ni and Zn) exhibit two absorption peaks in the range of 410–420 cm −1 and 580–600 cm −1 (Figure ) which assigned to the stretching frequency of the tetrahedral metal–oxygen bond and the metal–oxygen vibration at the octahedral sites in spinel compounds, respectively.…”

“…[37] However, some researchers consider the presence of an intense band at about 550 cm −1 to be sufficient proof for the formation of the spinel structure. [38] The typical FT-IR measurements for the prepared MFe 2 O 4 nanoparticles (M = Mn, Co, Ni and Zn) exhibit two absorption peaks in the range of 410-420 cm −1 and 580-600 cm −1 ( Figure 5) which assigned to the stretching frequency of the tetrahedral metal-oxygen bond and the metal-oxygen vibration at the octahedral sites in spinel compounds, respectively. The wavenumbers and intensity of the two characteristic bands corresponding to spinel ferrites are comparable with that reported previously.…”

The remanence ratio in CoFe2O4 nanoparticles with approximate single-domain sizes

“…These effects affect the magnetic properties and the magnetic ordering state of nanoparticles (NPs) individually, and sometimes synergetically which usually occurs in the dense magnetic NPs. One typical phenomenon of the size effect is that the coercivity ( H c ) reaches the maximum as the particle size ( D ) decreases to a single-domain critical dimension D c , and then reduces monotonically to zero when D is further decreased to a certain size below D c [9]. Concomitantly, the NPs exhibit the superparamagnetic behavior with the theoretical remanence ( M r ) to saturation ( M s ) magnetization ratio ( M r / M s ) being zero.…”

Effect of the CoFe2O4 initial particle size when sintered by microwave on the microstructural, dielectric, and magnetic properties

“…2,4,6,10,11 However, most of the CoFe 2 O 4 powders obtained using these routes often have a high surface area, which is why sintering using conventional methods is difficult, as high temperatures and long soaking times are required. 2,4,6,10,11 However, most of the CoFe 2 O 4 powders obtained using these routes often have a high surface area, which is why sintering using conventional methods is difficult, as high temperatures and long soaking times are required.…”

“…particles, aimed at obtaining fine particles with size, shapes, and controlled stoichiometry, as well as high coercivity for chemical and novel routes. 2,4,6,10,11 However, most of the CoFe 2 O 4 powders obtained using these routes often have a high surface area, which is why sintering using conventional methods is difficult, as high temperatures and long soaking times are required. Thus, few studies have addressed better sintering behavior, mainly in controlling their microstructure, focusing on the analysis of magnetic and electric properties for nanostructured systems overseeing the thermal stability and grain growth of nanocrystallites.…”