Effect of ferromagnetic cobalt on characteristics of coercive Aluminium substituted BaFe_11.5Al_0.5O₁₉ hexaferrites

Abstract

Magnetic and structural characteristics of M-type barium hexaferrite nanoparticles can be tuned by doping different di or trivalent metal ions. Here BaFe11.5-xAl0.5CoxO19 hexaferrite nanoparticles were synthesized using a sol-gel process, and the influence of doping concentrations on M-type BaFe11.5-xAl0.5CoxO19 hexaferrite nanoparticles was deliberated. The XRD analysis confirms the formation of ferrites successfully. When the doping level increased, the grain dimension (D) initially reduced and then increased. Similarly, the lattice constants ‘a’ and ‘c’ decreased initially and then increased. The findings indicated that the (Mr/Ms) ratio decreased initially as the doping content increased, but at higher doping ranges, it started to rise. At the same time, coercivity (Hc) and magneto-crystalline an-isotropy field (Ha) increased as the doping level increased. Excellent magnetic characteristics were obtained for BaFe11.5-xAl0.5CoxO19 hexaferrites at doping content of (x=1.5), with magnetic moment 10.80µB, saturation magnetization 57.35 emu/g, and coercivity 5.21 kOe along anisotropic applied field of 1.62 kOe. The findings mentioned above imply that magnetic characteristics of M-type Barium hexaferrites can be significantly improved upon doping of Cobalt against Aluminium substituted hexaferrite, which will make such types of Ba-hexaferrite very useful in many applications, for example, in magnetic filters, memory devices, and recording media, etc.

Microstructural, morphological and magnetic behaviour of Al3+ replaced BaFe11.5Co0.5O19 hexaferrites synthesized via sol-gel auto combustion route

“…The addition of Co may enhance the mechanical properties, such as hardness and fracture toughness. This will be useful for applications that require mechanical stability [36]. Because of their enhanced microwave absorption capabilities, Co-doped hexaferrites are helpful in radar technologies, communication systems, and microwave devices.…”

“…Cobalt-doped hexaferrites with regulated magnetic characteristics are useful for magnetic field sensors and compasses. The aerospace and automotive industries, for example, are situations where thermal stability is critical, and the presence of Co helps in maintaining or enhancing the magnetic characteristics at elevated temperatures [35,36]. Due to above mentioned possibilities, Co has been doped on pristine hexaferrite to prepare base samples of BaFe 11.5 Co 0.5 O 19 hexaferrites.…”