Physical and Magnetic Properties of Barium Calcium Hexaferrite Nano-particles Synthesized by Water-in-oil Reverse Micelle and Co-precipitation Techniques

Abstract

BaCaB2BFeB16BOB27B hexaferrite particles were prepared using two different techniques namely (i) reverse micelle and (ii) co-precipitation with and without presence of surfactants (cationic, anionic and nonionic). The precipitate was calcinated at 950˚C for 4 hours and characterized by using various instrumental techniques. The structural studies of the samples were studied by using XRD and SEM. The field dependent magnetic properties of prepared Ba-Ca hexaferrite powder was investigated at room temperature by using vibrating sample magnetometer. It has been observed that the type of surfactant plays a crucial role in deciding the morphology of the particles. There is significant change in crystallite size of the resultant Ba-Ca hexaferrite prepared in presence of anionic surfactant sodium dodecyl sulfate (SDS) and reverse micelle route. The samples prepared in presence of cationic and non ionic surfactants show agglomerated large particles. Magnetic study reveals that the value of anisotropy constant (K) depends on the type of surfactant used. The sample prepared in presence of nonionic surfactant Polyethylene glycol sorbitan monooleate (Tween 80) shows low anisotropy constant (0.26×10P-3P HAP2P/kg) where as the sample prepared in presence of SDS surfactant exhibits high anisotropy constant (3.26×10P-3 PHAP2P/kg) compared to normal sample (0.41 ×10P-3P HAP2P/kg).Keywords: Barium calcium hexaferrite particles; Surfactants; Structural and magnetic properties.© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i1.1684

Synthesis and characterization of aluminium substituted calcium hexaferrite

“…The coercivity of particles is determined by using magneto crystalline anisotropy constant K and saturation magnetization [3].…”

“…where K is Magneto crystalline anisotropy constant. The coercivity (H c ) of samples decreased with an increase in Al 3þ ion content is due to the decrease of magneto crystalline anisotropy [3].…”

“…Hexagonal ferrite possesses the hexagonal structure and is of the type of hard ferrite. Depending on chemical formulae and crystal structure hexagonal ferrites are divided into five types as M, W, X, Y and Z [3]. The general formula of M type hexaferrite is MFe 12 O 19 where M is usually divalent metal ion such as barium, strontium, calcium or Lead [4].…”

Influence of chromium substitution on structural and magnetic properties of BaFe12O19 powder prepared by sol–gel auto combustion method

“…It is commonly used as permanent magnets particulate media for magnetic recording as well as in microwave devices [1][2][3]. Hexagonal ferrites are divided into six different types M(AFe 12 [4]. Among these types barium hexaferrite is widely used due to its low production cost combined with excellent magnetic properties.…”

Effects of Divalent Ion Substitution on the Microstructure and Magnetic Properties of SrCo 2−x (MnZnCa) x/3Fe 1 6 O 2 7 Nanoparticles

“…Various techniques such as chemical co-precipitation [9,10], sol-gel [11,12], standard ceramic [13,14], microemulsion, and reverse micelle [15] were employed for the synthesis of hexaferrites. Among these different techniques, chemical co-precipitation method is found to be very suitable because of its simplicity, lower cost, and comparatively lower annealing temperature and annealing time to achieve the pure single phase.…”