Preparation and characterization of various morphologies of SrFe12O19 nano-structures: investigation of magnetization and coercivity

Novel Gd2O3/SrFe12O19@Schiff base chitosan (Gd/SrFe@SBCs) nanocomposite as a novel magnetic sorbent for the removal of Pb(II) and Cd(II) ions from aqueous solution

“…[7] Two peaks were observed at 1,472 and 1,073 cm À1 assigned to the stretching vibration of C-O-C and C-N groups, respectively, [7,8] Finally, three weak peaks were observed at 611, 564, and 464 cm À1 to predict the Fe-O, Sr-O, and Gd-O vibration. [6,8,[41][42][43][44][45][46][52][53][54] Figure 2 shows the XRD patterns of Gd/SrFe and its Gd/SrFe@SBCs nanocomposite for Gd/SrFe@SBCs, the XRD peaks observed at 2θ value of 20.73 correspond to the pure chitosan and a shoulder peak at 2θ value of 15 correspond to the Schiff base chitosan. [6][7][8]27,28] In addition, the peaks at 2θ value of 28.87, 32.95, 47.17, and 57.02 correspond to the (222), (400), (440), and (622) planes of the cubic phase of Gd 2 O 3 [52][53][54] and those at [41][42][43][44][45][46] The average crystallite sizes of Gd 2 O 3 and SrFe 12 O 19 in Gd/SrFe were calculated at about 51 and 36 nm, respectively, using Scherrer equation, d = 0.94λ/β cosθ, where d is the crystalline size (nm), λ is the wavelength of the X-ray radiation (1.54 Å), β is FWHM, and θ is Bragg's angle.…”

“…[6,8,[41][42][43][44][45][46][52][53][54] Figure 2 shows the XRD patterns of Gd/SrFe and its Gd/SrFe@SBCs nanocomposite for Gd/SrFe@SBCs, the XRD peaks observed at 2θ value of 20.73 correspond to the pure chitosan and a shoulder peak at 2θ value of 15 correspond to the Schiff base chitosan. [6][7][8]27,28] In addition, the peaks at 2θ value of 28.87, 32.95, 47.17, and 57.02 correspond to the (222), (400), (440), and (622) planes of the cubic phase of Gd 2 O 3 [52][53][54] and those at [41][42][43][44][45][46] The average crystallite sizes of Gd 2 O 3 and SrFe 12 O 19 in Gd/SrFe were calculated at about 51 and 36 nm, respectively, using Scherrer equation, d = 0.94λ/β cosθ, where d is the crystalline size (nm), λ is the wavelength of the X-ray radiation (1.54 Å), β is FWHM, and θ is Bragg's angle. DSC thermogram of Gd/SrFe@SBCs (Figure 3) shows an endothermic peak at 82.6 C assigned to evaporation of solvent, [27,28,55] and exothermic peaks at 285.5 C are assigned to the thermal decomposition of C=N, pyranose and aromatic rings of Gd/SrFe@SBCs.…”

“…DSC thermogram of Gd/SrFe@SBCs (Figure 3) shows an endothermic peak at 82.6 C assigned to evaporation of solvent, [27,28,55] and exothermic peaks at 285.5 C are assigned to the thermal decomposition of C=N, pyranose and aromatic rings of Gd/SrFe@SBCs. [27,28,55] The magnetic hysteresis loop of Gd/SrFe and its Gd/SrFe@SBCs nanocomposite (Figure 4) show high coercivity (H c ) of 4,664 Oe, with saturation magnetizations (M s ) of 17.35 emu/g for Gd/SrFe and 9.96 emu/g for Gd/SrFe@SBCs, and a remnant magnetization (M r ) of 9.14 emu/g for Gd/SrFe and 5.21 emu/g for Gd/SrFe@SBCs, known as hard magnetic materials, [41][42][43][44][45][46] which was beneficial to its recycling from solution after used as sorbent using an external magnet. The M s and M r of Gd/SrFe@SBCs nanocomposite are lower than Gd/SrFe, due to the presence of chitosan Schiff base.…”

“…Strontium hexaferrite (SrFe 12 O 19 ) known as hard magnetic materials due to its high coercivity [41][42][43][44] and its nanocomposites have received much attention in recent years. [45][46][47][48][49][50][51] Gd 2 O 3 nanoparticles are chemically and thermally stable, n-type semiconductor, and high dielectric constant has received much attention in various applications.…”

Synthesis of Ultra‐fine Co1‐(x+y)NixZnyFe2O4 Ferrite Nanoparticles: Customizing Magnetic Properties

“…In this paper, in the presence of citric acid, Cobalt, Nickel, and Zinc ion concentrations have been tuned to reduce the toxicity of MNPs and find a good pattern. There are different synthesis methods for ferrite MNPs such as auto-combustion synthesis, co-precipitation method [33,[38][39][40][41] , mechanical alloying [42] , sol-gel [2,43] , and so on. Each method has advantages over the other methods.…”