Microstructure and hysteresis curves of the barium hexaferrite from co-precipitation by organic agent

Performance of radar absorbing nanocomposites by waveguide measurements

“…The magnetization curves of the product synthesized in this work show typical features of magnetically soft materials and we can observe a decreasing coercive force (H c ) and the remanent magnetization (B r ) when calcination temperature is increased, a behavior consistent with the disappearance of the M-type phase and increasing Z-type phase 6,[7][8][9][10][11][12] . The powder calcined at 900 °C does not also presented magnetic saturation, which was only achieved in the product from calcination at 950 °C during 4 hours (magnetization of 45.1 emu/g and a coercive force of 110 Oe).…”

“…Then, the use of inert atmosphere effectively reduce the temperature required to form Z-type hexaferrite, a behavior remarkably different from that when the same starting mixture undergoes synthesis in air (instead of inert atmosphere), in which case calcined product consisted of: a) a mixture of Y and M-types at 1000 °C; b) only at 1150 °C Z-type phase peaks were found out 8 . However, this material synthesized in inert atmosphere contains according to Pullar et al 11 small undetectable amounts of Y-type phase (Ba 2 Co 2 Fe 12 O 22 ) coexisting with the Z-type phase.…”

“…All the synthesis process was carried out under super-dry nitrogen atmosphere in order to prevent the contact of the solutions with contaminants, mainly the carbon dioxide [6][7][8] . Determination of an ideal temperature for the citrate gel decomposition, as well as all the behavior of the complex under heating was carried out by using thermogravimetric analysis (TGA) and differential thermal analysis (DTA).…”

Preparation of barium hexaferrite powders using oxidized steel scales waste

“…Another upside is that it has relatively lower price than other types of permanent magnets such as rare earth, AlNiCo, or SmCo magnets. This compound is used in magnetic recording, microwave device [3], and absorber.…”

“…Commercial ceramic making or solid state reaction is a conventional way to synthesis barium hexaferrite powders using stoichiometric mixture of barium carbonate and iron oxide and firing at high temperature [4]. Other methods to prepare barium hexaferrite are through co-precipitation method [3,5], sol-gel method [6], and hydrothermal method [7]. Solid state reaction is chosen because of its low cost, no complex chemical involved and relatively has simple processes.…”