Influence of sintering temperature on structural, morphological and magnetic properties of barium hexaferrite nanoparticles

Abstract

Barium hexaferrite nanoparticles are attractive for modern data storage and microwave devices due to their unique properties. Single phase synthesis of barium hexaferrite using sol–gel auto-combustion route was optimized by varying sintering temperature and time. X-ray diffraction confirmed single phase hexagonal crystal structure of the sample sintered at 1100[Formula: see text]C for 2 h. Crystallite size, as determined using Scherrer’s formula, was increased with the increase in sintering temperature while the porosity remained nearly unchanged. Field emission scanning electron microscope (FE-SEM) revealed that grain size was increased from nanometers to micrometers by rising the sintering temperature and the shape of particles was platelet-like hexagonal at 900[Formula: see text]C. Vibrating sample magnetometer (VSM) exhibited that saturation magnetization and coercivity increased with the increase of sintering temperature. Maximum saturation magnetization and coercivity values were 36.80 emu/g and 5365 Oe, respectively, for the sample sintered at 1100[Formula: see text]C for 2 h.

Effect of Ratio in Ammonium Nitrate on the Structural, Microstructural, Magnetic, and AC Conductivity Properties of BaFe12O19

“…Large amounts of AN salts yielded a large amount of diamagnetic substances in a ferromagnetic BF system. A sample ratio of 1:3 produced maximum magnetic properties with the values of H c being 1317 Oe, M s being 90.85 emu/g, and M r being 43.83 emu/g, which was higher compared to other methods for synthesizing BaFe 12 O 19 [4,61,62,63]. The value of magnetization, M s , of the sample ratio 1:3 was higher than that of single crystals ( M s is 72 emu/g) due to the formation of high-weight fractions of magnetic phases in the samples.…”

Magnetic, gas sensing properties, and structural parameters of barium–calcium hexaferrite synthesized by sol‐gel auto combustion method

“…The magnetic characteristics of Ba 1Àx Ca x Fe 12 O 19 (where x = 0, 0.2, 0.4) compounds were recorded at room temperature using a VSM at maximum magnetic field of 1.5 T. The magnetic hysteresis loops are shown in Figure 5. Magnetic characteristics including saturation magnetization (M s ), coercivity (H c ), and remnant magnetization (M r ) for all synthesized samples are extracted from the hysteresis loops and are summarized in [3] type of bond between particles or agglomerates, [16] degree of homogeneity or heterogeneity, particle distribution, [30] crystal grain size, and replacement of Fe or Ba ions with impurity cations. [28] The results of the magnetic data show that the saturation magnetization (M s ) increases with higher level of the spinel phase of barium ferrite and decreases with higher level of barium-calcium ferrite spinel and particularity, nonspinel compounds such as BaFe 2 O 4 , α-Fe 2 O 3 , and CaFe 2 O 4 .…”

“…In studies of the synthesis of barium hexaferrites by combustion sol-gel method, the effects of various parameters including molar ratio of citric acid to nitrate (barium nitrate + iron nitrate + metal nitrate related to alternative cation), [29] pH changes, [3] sintering temperature, [30] the molar ratio of iron to barium, [31] and the substitution of barium cations with different cations such as La, Pr, Ti, Co, Bi, Ni, Cr, Cs, Mg, Zn, and Sn [32][33][34] on physical, magnetic, and sensing properties have been investigated. However, limited studies have been performed on the substitution of barium cation in barium hexaferrite with calcium and its effect on changes in magnetic and especially in gas sensing properties.…”

EFFECT OF Mn AND Ti ADDITION ON THE CRYSTALLOGRAPHIC STRUCTURE AND MAGNETIC PROPERTIES OF SrFe12O19

“…The problem faced in a ferrite-based magnetic material that will be the object of this study is the magnetocrystalline anisotropy constant of this compound has relatively high value of ~ 330 kJ/m 3 . This value is very high and causes the material has relatively large coercivity about ~ 1500 kA.m -1 which is needed as a permanent magnet [11][12][13][14][15]. However, as an absorber material of electromagnetic waves (microwave absorber) must have a coercivity value as low as possible so that the magnetic loss is low, but should still have a high value of the total magnetization.…”