Effect of Al-substitution on phase formation and magnetic properties of barium hexaferrite synthesized with sol-gel auto-combustion method

Abstract

Al-substituted barium ferrite powders were synthesized using the sol-gel auto-combustion method according to the molecular formula BaAlxFe12−xO19 (x=0, 0.1, 0.2, 0.3, 0.4, 0.5, 1.0). Compared with non-substituted barium ferrite annealing at 1 000 ℃, the vibrating sample magnetometer (VSM) measurement manifested that the optimum magnetic properties formation temperature of Al-substituted barium ferrite was 1 100 ℃. The data from X-ray diffractometer (XRD) showed that with increasing x, the lattice constants (a and c) decreased as well as the unit-cell volume V cell . Magnetic measurement of non-substituted and Al-substituted powders annealed from 900 ℃ to 1 200 ℃ exhibited that the maximum magnetization M (10 kOe), the remanent magnetization Mr and the coercivity Hc depended strongly on the chemical composition of powder as well as the annealing temperature. When annealing at 1 100 ℃, BaAl0.5Fe11.5O19 of high coercivity Hc (6 584 Oe) was produced. Meanwhile, M (10 kOe) and Mr were 42.83 emu/g and 25.65 emu/g, respectively.

Sintesis dan Karakterisasi Barium Heksaferit dengan Variasi Pengurangan Massa Fe2O3

“…Jadi setiap satu kristal barium heksaferit terdapat 2 atom Ba, 24 atom Fe, dan 38 atom O [1]. Dalam upaya untuk membuat Barium Heksaferit, terdapat Beberapa metode yang dikembangkan untuk membuat barium heksaferit, seperti solid state reaction [2], sol-gel [3,4], metode glass-ceramic [5], metode glass crystallization [6], metode liquid mix [7], metode keramik [8], aerosol rute [9] dan teknik hydrothermal [10,11].…”

Effect of Mg Substitution on Microwave Absorption of BaFe₁₂O₁₉

“…The substituted M-hexaferrites are of technological interest in microwave applications because ferromagnetic resonance frequency and thus the absorbing frequency band can be controlled by the substitution rates [5]. Barium ferrite is often substituted with tetravalent and divalent, non-magnetic and magnetic cations like Co, Zn, Ti, Mo, Al, Ni [6][7][8]. However, there are no reports of Mg substitution on microwave absorbing properties barium hexaferrites.…”