One-step synthesis of barium hexaferrite nano-powders via microwave-assisted sol–gel auto-combustion

Solution–processing methods were investigated as viable alternatives to produce the polymer-bonded barium hexaferrite (BaM). BaM powders were first synthesized by using the sol-gel auto-combustion method. While the ignition period in two synthesis batches varied, the morphology of hexagonal microplates and nanorods, as well as magnetic properties, were reproduced. To prepare magnetic polymer composites, these BaM powders were then incorporated into the acrylonitrile-butadiene-styrene (ABS) matrix with a weight ratio of 80:20, 70:30, and 60:40 by using the solution casting method. Magnetizations were linearly decreased with a reduction in ferrite loading. Compared to the BaM loose powders and pressed pellet, both remanent and saturation magnetizations were lower and gave rise to comparable values of the squareness. The squareness around 0.5 of BaM samples and their composites revealed the isotropic alignment. Interestingly, the coercivity was significantly increased from 1727–1776 Oe in loose BaM powders to 1874–2052 Oe for the BaM-ABS composites. These composites have potential to be implemented in the additive manufacturing of rare-earth-free magnets.

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Magnetic and Structural Properties of Barium Hexaferrite Nanoparticles Doped with Titanium

Symmetry ◽

10.3390/sym11060732 ◽

2019 ◽

Vol 11 (6) ◽

pp. 732 ◽

Cited By ~ 1

Author(s):

Abdul Raouf Al Dairy ◽

Lina A. Al-Hmoud ◽

Heba A. Khatatbeh

Keyword(s):

Saturation Magnetization ◽

Permanent Magnets ◽

Sol Gel ◽

Hysteresis Loops ◽

Barium Hexaferrite ◽

Titanium Concentration ◽

Recording Equipment ◽

Auto Combustion ◽

Xrd Patterns ◽

Combustion Technique

Samples of Barium Hexaferrite doped with Titanium BaFe12−xTixO19 with (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) were synthesized by the sol–gel auto-combustion technique. The powdered samples were divided into two parts, one sintered at 850 °C and another sintered 1000 °C for 1 h and samples were characterized by different experimental techniques. The XRD patterns confirmed the presence of M-type hexaferrite phase. The sizes of the crystallites were calculated by the Scherer equation, and the sizes were in the range of 27–42 nm. Using the hysteresis loops, the saturation magnetization Ms, remanence (Mr), the relative ratio (Mr/Ms), and the coercivity (Hc) were calculated. The study showed that the saturation magnetization (Ms) and remanence (Mr) decreased with increasing titanium concentration and were in the range from 44.65–17.17 emu/g and 23.1–7.7 emu/g, respectively. The coercivity (Hc) ranged between 0.583 and 4.51 (kOe). The magnetic properties of these Barium Hexaferrite doped with Titanium indicated that they could be used in the recording equipment and permanent magnets.

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Microwave assisted sol-gel auto-combustion synthesis of NiCuFe2O4 nanoparticles using citric acid as an organic chelating agent: structural and optical studies

10.3390/ecsoc-19-c005 ◽

2015 ◽

Author(s):

Faranak Manteghi ◽

Mahnaz Kamel Attar Kar ◽

Mahdi Ghahari

Keyword(s):

Citric Acid ◽

Combustion Synthesis ◽

Sol Gel ◽

Chelating Agent ◽

Optical Studies ◽

Microwave Assisted ◽

Auto Combustion

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Dielectric Characteristics of Donor Doped Nonlead Ba(Cu1/3Nb2/3)O3 Perovskite Material Synthesized by Microwave-assisted Citrate-nitrate Sol-gel Route

MRS Proceedings ◽

10.1557/proc-0997-i06-05 ◽

2007 ◽

Vol 997 ◽

Author(s):

Alp Manavbasi ◽

Jeffrey C LaCombe

Keyword(s):

Sol Gel ◽

Particle Morphology ◽

Ferroelectric Ceramic ◽

Copper Nitrate ◽

Correlation Spectroscopy ◽

Nanocrystalline Powders ◽

Microwave Assisted ◽

Precursor Material ◽

Auto Combustion ◽

Diffraction Patterns

AbstractNonlead perovskite type, Ba(Cu1/3Nb2/3−xWx)O3 (x = 0, 0.025), ferroelectric ceramic powders (BCN) were prepared by the microwave-assisted citrate-nitrate sol-gel technique. The gel was formed from a stable and homogeneous sol prepared by mixing stable solutions of barium- and copper-nitrate, tungsten citrate, and peroxo-citrato-niobium precursors. Microwave irradiation of the gel resulted in a dark, fluffy precursor material after auto-combustion. Calcination of the as-combusted samples produces a single phase with tetragonal splitting in X-Ray diffraction patterns. The crystallite size of the synthesized samples was found to be 41 nm. Particle morphology and the size of nanocrystalline powders were characterized by scanning electron microscopy and photon correlation spectroscopy, respectively. Electrical and dielectric properties of sintered samples were investigated by impedance spectroscopy. The isothermal ac measurements were performed from room temperature, up to 600 °C for W6+ doped and undoped BCN samples.

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Synthesis and characterization of Jamun pulp based M-type barium hexaferrite via sol–gel auto-combustion

Results in Physics ◽

10.1016/j.rinp.2021.103903 ◽

2021 ◽

Vol 22 ◽

pp. 103903

Author(s):

Sachin Kumar Godara ◽

Rahul Kumar Dhaka ◽

Navpreet Kaur ◽

Parambir Singh Malhi ◽

Varinder Kaur ◽

...

Keyword(s):

Sol Gel ◽

Barium Hexaferrite ◽

Synthesis And Characterization ◽

Auto Combustion

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Synthesis of (Ba,Ti)-Doped Apatite-Type Lanthanum Silicate Nano-Sized Powders via Microwave-Assisted Sol-Gel Auto-Combustion Route

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.652-654.882 ◽

2013 ◽

Vol 652-654 ◽

pp. 882-885 ◽

Cited By ~ 1

Author(s):

Ran Wu ◽

Jia Mei Ye ◽

Qi Zhao Li ◽

Sheng Yun Wang ◽

Xiu Lei Chen ◽

...

Keyword(s):

Particle Size ◽

Citric Acid ◽

Sol Gel ◽

Lanthanum Nitrate ◽

Microwave Assisted ◽

Auto Combustion ◽

Combustion Route ◽

Lanthanum Silicate ◽

Apatite Type

In this paper, (Ba,Ti)-doped lanthanum silicate nano-sized powders have been synthesized via microwave assisted sol-gel auto-combustion route by using TEOS and lanthanum nitrate as the starting materials, citric acid and glycol as chelators. Both the phase compositions and morphologies of the obtained powders have been characterized. The results indicated that: the synthesized nano powders were characterized as fluffy aggregates with the particle size ranging from 50 to 100nm. As the doping contents of Ba increased, the crystalline sizes decreased and the aggregation were deteriorated, while the particle size decreased from 120nm to 80nm and the aggregation between particles were halted as the doping contents of Ti increased.

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