Magnetic properties of BaNixFe12–xO19 (x=0.0–1.0) hexaferrites, synthesized by citrate–gel auto-combustion and sintered by conventional and spark plasma methods

Tailoring the optical and magnetic properties of La-BaM hexaferrites by Ni substitution

“…The substitution of Ni 2+ (2µ B ) ions at the Fe 3+ (5µ B ) ion sites is responsible for the decrease in saturation magnetization with increasing Ni 2+ concentration. [15,20,31,45] The saturation magnetization values that are achieved in this study for Ni 2+ free samples are compared with the values reported in the literature [4,9,20,[45][46][47] and are found to be significantly higher. The higher values of saturation magnetization achieved are attributed to the vacancy free nature of the samples and the presence of paramagnetic La 3+ cations at the spin-up (12k, 2a, and 2b) sites.…”

“…Hexagonal ferrites are divided into five sub-categories based on their crystal structure and chemical formula: M-type (AFe 12 O 19 ), W-type (AFe 16 O 27 ), X-type (AFe 28 O 46 ), Y-type (AFe 12 O 22 ), Z-type (AFe 24 O 41 ), where A is the divalent cation like Ba 2+ , Sr 2+ , Pb 2+ , Ca 2+ [5][6][7]. Among these, M-type hexaferrite has gained more attention due to its distinguished properties like very high magnetic anisotropy, higher coercivity, higher corrosion resistance, high thermal and chemical stability [8][9][10][11]. Barium M-type (BaM) hexaferrite are ferrimagnetic materials with the chemical formula BaFe 12 O 19 and space group P6 3 /mmc.…”

“…[5][6][7] Among these, M-type hexaferrites have gained more attention due to their distinguished properties, such as their very high magnetic anisotropy, higher coercivity, higher corrosion resistance, and high thermal and chemical stability. [8][9][10][11] Barium M-type (BaM) hexaferrites are ferrimagnetic materials with the chemical formula BaFe 12 O 19 and the space group P6 3 /mmc. They consist of tetrahedral (4 f 1 ), octahedral (12k, 4 f 2 , and 2a), and hexahedral (2b) sites.…”

“…Various reports have been published on the topic of modifying the microstructure, electrical, dielectric, optical, and magnetic properties of BaM hexaferrite by replacing the Fe 3+ and Ba 3+ cations with divalent and trivalent cations. Recently, Cernea et al [9] reported the magnetic properties of Ni 2+ substituted BaFe 12 O 19 hexaferrite. They observed a decreasing trend in the coercivity, retentivity, and maximum energy product with an increase in Ni 2+ .…”

Influence of Gd and Ni doping on the structural, morphological, and magnetic properties of M-type calcium hexaferrite

“…83 The M s and M r significantly increase due to smaller crystal ionic radii of Gd 3+ (107.5 pm) as compared to the crystal ionic radii of Ca 2+ (114 pm) 84 and due to the substitution of Ni ions for Fe ions in the spin-down state additionally causes high canting, particularly at the 4f 1 locations. 85 Hence, the substitution of Gd 3+ and Ni 2+ ions could increase the total magnetic moment to increase magnetization. In M-type hexaferrites, when Fe 3+ ions are replaced by divalent ions such as Ni 2+ , the charge balance is most likely accomplished through the development of vacancies on the five crystallographic sites.…”