Physical properties of Al-doped cobalt nanoferrite prepared by citrate–nitrate auto combustion method

Synthesis and characterization of ultrasmall MgFe2O4 nanoparticles down to the quantum dot scale

“…The fitting of M(H) of different MgFe2O4 nanoparticles is shown in Figure (9a-c), where the values of K and Ha are presented in Table (4) and Figure (9c,d). As indicated in Table (4) and Figure (9b), considerable differences between the values of saturation magnetization calculated from the fitting (Eq. 18) and that obtained directly from the hysteresis loops.…”

“…Spinel ferrite nanoparticles have several industrial and biomedical applications [1,2]. The structural, elastic, electrical, and magnetic properties of these materials are strongly affected by the chemical composition and microstructure, which are very sensitive to the preparation methods and conditions [3,4]. For spinel ferrite nanoparticles, changing the preparation conditions yields different particle sizes and morphology.…”

Synthesis and characterization of Co-doped Manganese ferrite nanoparticles

“…The two characteristic vibrational bands; νt (450-650 cm−1) and νo (250-400 cm −1 ) belong to the tetrahedral and octahedral sites, respectively. Each band contains more than one vibrational frequency, which can be attributed to the difference in the atomic masses of different ions (Fe, Mn, and Co), bond lengths, and the correlation between A-site complexes and the B-site [21][22][23][24]. The presence of secondary Mn oxide phases for samples Mn1-xCoxFe2O4 (x=0, 0.25, 0.5) will logically complicate the FTIR response and cause additional vibrational frequencies.…”

The structure, and magnetic properties of NiR0.05Fe1.95O4 (rare earth R=Sm, Gd): Effect of Thermal Neutron Radiation

“…The νt1, νt2 are assigned to the vibrational modes at the tetrahedral A-site, whereas, νo1, νo2, and νo3 are associated with the vibrational modes at the octahedral B-site. Generally, spinel ferrites have two characterized FTIR bands, νt and νo, associated with the vibrations of the bond between oxygen ion sites of cation sites in both tetrahedral (A) and octahedral (B) sites, respectively [25][26][27]. The energy required to stretch (cation-Oxygen) bond at the B-site is smaller than that of A-site since the bond length at the octahedral site is longer than that of the tetrahedral site [28,29].…”

“…The decrease of a (from the XRD measurements) will decrease interatomic spacing and lead to shortening of bond lengths, hence the U would decrease [32]. However, the decreased values of the lattice energy with increasing the exposure dose can be attributed to the increase of the elastic parameters and the enhanced particle size [25,32]. As mentioned before, the NiFe1.95Gd0.05O4 compound is more sensitive to thermal neutron exposure than the NiFe1.95Sm0.05O4 compound, which is reflected in the changes in the elastic properties of the two compounds.…”