Synthesis and magnetic properties of barium–calcium hexaferrite particles prepared by sol–gel and microemulsion techniques

Magnetic chitosan/iron (II, III) oxide nanoparticles prepared by spray-drying

“…Superparamagnetic iron oxide nanoparticles include ␥-Fe 2 O 3 and Fe 3 O 4 , among others (Chatterjee, Haik, & Chen, 2003;Kim, Ahn, & Lee, 2007;Neuberger, Schöpf, Hofmann, Hofmann, & Rechenberg, 2005;Sun, Ma, Zhang, & Gu, 2004). These can be produced using the bulk solution method (Sun et al, 2004), the sol-gel method (Jotania, Khomane, Chauhan, Menon, & Kulkarni, 2008), the aerosol/vapour (pyrolysis) method (Racka, Gich, Waniewska, Roig, & Molins, 2005), the gas deposition method (Rellinghaus, Stappert, Acet, & Wassermann, 2003), and the microemulsion method (Jia, Yujun, Yangcheng, Jingyu, & Guangsheng, 2006;Jotania et al, 2008). Magnetic iron oxide nanoparticles have features of superparamagnetism, high coercive force, and small-size effect (Huber, 2005;Neuberger et al, 2005).…”

Study of the dielectric and magnetic properties of Co2Y, Y-type hexaferrite (Ba2Co2Fe12O22) added with PbO and Bi2O3 in the RF frequency range

“…They have been classified according to their structure into six main classes: M-type or BaFe 12 60 where Me represents a divalent ion from the first transition series [5]. Among them, Y-type ferrite is constructed from basic units of hexagonal barium M ferrite [6] and cubic spinel ferrites, which retain a hexagonal structure, usually with the direction of magnetization parallel to the c-axis.…”

HYSTERESIS AND ELECTRIC MODULUS ANALYSIS OF Y³⁺ DOPED MnNi-Y-TYPE HEXAGONAL FERRITE

“…Drift mobility of all the samples were calculated using the relation (1) where e is the charge of electron, ρ is resistivity and n is the concentration of charge carrier and can be calculated from the well-known equation; (2) where N A is the Avogadro's number, d b is the measured bulk density of sample, P Fe is the number of iron atoms in the chemical formula of the ferrites and M is the molecular weight of the samples. The drift mobility is related to the temperature by following relation (3) where μ o is pre-exponential constant, k B is Boltzmann constant and Eμ is the activation energy for mobility of ions.…”

“…Hexagonal ferrites have attracted much attention since their discovery by Philips in the 1950s [1].These materials have large utility in the field of material science. These are important magnetic materials that, find its application in almost 70 -80 % of the electronic materials such as home appliances, communication equipment and data processing devices [2,3]. Having a high coercivity and moderate magnetization, hexaferrites are valuable from technological point of view.…”