Article
Chemistry, Multidisciplinary
Lev A. Trusov, Anastasia E. Sleptsova, Jingtong Duan, Evgeny A. Gorbachev, Ekaterina S. Kozlyakova, Evgeny O. Anokhin, Artem A. Eliseev, Maxim A. Karpov, Alexander V. Vasiliev, Oleg A. Brylev, Pavel E. Kazin
Summary: A method to prepare nonsintered single-domain nanoparticles of chromium-substituted hexaferrite via crystallization of glass in the system SrO-Fe2O3-Cr2O3-B2O3 was successfully demonstrated, showing plate-like hexaferrite nanoparticles with diameters changing from 20 to 190 nm. Chromium substitution significantly improved the coercivity of the particles, ranging from 334 to 732 kA m(-1), providing a new strategy for producing high-coercivity ferrite nanomagnets.
Article
Materials Science, Ceramics
Ruoshui Liu, Lichen Wang, Xiang Yu, Zhiyi Xu, Huayang Gong, Tongyun Zhao, Fengxia Hu, Baogen Shen
Summary: The study demonstrates the enhancement of magnetocrystalline anisotropy (MA) in La-Co co-substituted strontium hexaferrite (La-Co SrM) due to the joint effect of Fe2+ and Co2+ ions. Co-substituted strontium hexaferrite SrFe12-xCoxO19 (Co-SrM) single crystals were grown to investigate the anisotropy of Co2+ single ions. The solubility of Co in this preparation condition is limited to 0.31, and for 0.03 < x <= 0.11, a 19% enhancement in uniaxial magnetic anisotropy field HA is observed, with only a 7% loss in saturation magnetization MS at 5 K. The enhanced HA of Co-SrM is even higher than that of La-Co SrM, making it suitable for use as permanent magnets in this concentration range. However, for x = 0.31, planar anisotropy is observed at 5 K. The potential nonlinear magnetic structure of Co-SrM remains to be discovered for magnetoelectric effects. This work serves as a significant complement to the magnetocrystalline anisotropy study of La-Co SrM.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Marian Stingaciu, Durgamadhab Mishra, Cesar de Julian Fernandez, Riccardo Cabassi, Anna Zink Eikeland, Mogens Christensen, Stefano Deledda
Summary: The structural and magnetic properties of Sr0.67Ca0.33Fe9Al3-xCrxO19 submicrometric powders with substitution levels ranging from x = 0 up to x = 3, prepared by sol-gel synthesis method, have been investigated. The Ca-Al-Cr substituted strontium hexaferrite shows a correlation between the structure and magnetic properties, and the role of particle size in maximizing coercivity properties is discussed.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Inorganic & Nuclear
Akanksha Gupta, P. K. Roy
Summary: In this study, the composition of sol-gel auto-combustion synthesized SrFe8-xAl4ZnxO19 (0 < x < 1) hexaferrites is investigated in order to improve the magnetic parameters of strontium hexaferrite magnets. The substitution of Zn in SrFe8Al4O19 hexaferrite is found to effectively enhance the energy density (BH)max to 19.15 MGOe, making it a cost-effective option for various permanent magnet applications. The dielectric properties exhibit typical behavior of hexaferrites, which can be explained by the Maxwell-Wagner theory and the Koop model. This research is expected to offer an economic and efficient alternative to rare-earth-based permanent magnets.
INORGANIC CHEMISTRY COMMUNICATIONS
(2023)
Article
Physics, Condensed Matter
Sushree Nibedita Rout, Murli Kumar Manglam, Jyotirekha Mallick, Subhadeep Datta, Manoranjan Kar
Summary: Al-substituted strontium hexaferrite (SrFe12-xAlxO19) was synthesized by the sol-gel auto-combustion method and microwave sintering at 1100 degrees C. The XRD patterns showed hexagonal crystal symmetry with P6(3)/mmc space group. Lattice contraction was observed with increasing Al3+ concentration in SrFe12-xAlxO19. The anisotropy field was found to be approximately 25 kOe for SrFe11.5Al0.5O19. The (BH)(max) of 1.20 MGOe was obtained for x = 0.0, while there was a 63.66% enhancement of coercivity for SrFe11.5Al0.5O19 at 300 K. However, the highest (BH)(max) of 1.84 MGOe was achieved at 60 K for SrFe11.5Al0.5O19. The hardness parameter analysis confirmed that all the samples met the criterion for a permanent magnet, with (BH)max in the range of (1.00-1.20) MGOe at 300 K.
PHYSICA B-CONDENSED MATTER
(2023)
Article
Physics, Condensed Matter
V. Banihashemi, M. E. Ghazi, M. Izadifard
Summary: In this study, Sr1-xCaxFe12-yZnyO19 hexaferrites were prepared through the sol-gel combustion method and their structural, magnetic, and optical properties were investigated. X-ray diffraction and Fourier transform-infrared spectroscopy confirmed the formation of hexaferrite phases. The saturation magnetization decreased and coercivity increased with higher substitution concentration. Reflectance spectra showed an increase in bandgap energy values with increased substitution content.
PHYSICA B-CONDENSED MATTER
(2021)
Article
Materials Science, Multidisciplinary
K. Subrahmanya Sarma, Ch. Rambabu, G. Vishnu Priya, M. K. Raju, D. Parajuli, Batoo Khalid Mujasam, Verma Ritesh, Kumar Rajesh, N. Murali, P. V. Lakshminarayana
Summary: M-type Al-Cr-substituted strontium hexaferrite powders were successfully synthesized and their structural, morphological, and magnetic properties were studied. The results showed that the saturation magnetization decreased and the coercivity initially decreased and then increased with increase in dopant concentration.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
M. F. Ramirez-Ayala, A. Lobo Guerrero, A. M. Herrera-Gonzalez, T. J. Perez-Juache, R. Lopez-Juarez, J. T. Elizalde-Galindo, V. E. Salazar-Munoz, S. A. Palomares-Sanchez, S. Y. Reyes-Lopez
Summary: This study investigates the effects of neodymium on the microstructural, magnetic, and structural properties of strontium hexaferrite. Neodymium is partially incorporated into the hexaferrite crystal structure, forming neodymium orthoferrite as a second phase, which significantly impacts the magnetic properties. The temperature and neodymium content were varied to analyze their effects on the hexaferrite properties. X-ray diffraction, Rietveld refinement, vibrant sample magnetometry, and electron microscopy were used to evaluate the behavior, structural properties, magnetic properties, and microstructural characteristics. The incorporation of neodymium and magnetic interactions between the hexaferrite and neodymium orthoferrite resulted in a 35% increase in the maximum energy product compared to neodymium-free hexaferrite.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2023)
Article
Chemistry, Physical
Santhoshkumar Mahadevan, A. Ravi Sankar, Sonal Singh, Puneet Sharma
Summary: Gd-substituted barium hexaferrite was synthesized and its X-band absorption and shielding performance were investigated. The synthesized hexaferrite was characterized using XRD, micro-Raman spectroscopy, FESEM, VSM, and VNA. The results showed the formation of the hexagonal magnetoplumbite phase and the presence of Fe2+ ions at specific sites. Gd substitution led to reduced particle size and improved magnetization, remanence, shielding efficiency, and absorption. The material exhibited up to 97% improvement in microwave absorbance with Gd substitution, suggesting its potential application as a microwave absorber.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Physics, Multidisciplinary
Singh Sonu Kumar, Rakesh Kumar Singh, Pammi Kumari, Narender Ranga, Aniket Manash, Rekha Kumari
Summary: This study synthesized rare earth boron strontium hexaferrite samples using sol-gel technique and conducted characterization analysis. The results showed that the samples exhibited hexagonal symmetry, and the lattice constants varied with the yttrium content. The morphological structure and grain size of the samples were observed through micrographs, TEM, and HRTEM. Raman and FTIR spectroscopy revealed the vibration modes and chemical bonding of the synthesized samples. Fluorescence spectroscopy and UV-Visible spectroscopy investigated the luminescent properties and band gap characteristics of the samples.
Article
Materials Science, Multidisciplinary
Evgeny A. Gorbachev, Lev A. Trusov, Mingxi Wu, Alexander V. Vasiliev, Roman D. Svetogorov, Liudmila N. Alyabyeva, Vasily A. Lebedev, Anastasia E. Sleptsova, Maxim A. Karpov, Yaroslav M. Mozharov, Boris P. Gorshunov, Pavel E. Kazin
Summary: This study demonstrates the synthesis and investigation of the magnetostatic and magnetodynamic properties of single-domain gallium substituted strontium M-type hexaferrite particles. Introduction of Ga3+ ions leads to an increase in coercivity, with further increase in gallium concentration causing a decrease in coercivity. The samples display a natural ferromagnetic resonance frequency.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Chemistry, Inorganic & Nuclear
Cong Zhang, Shuangjiu Feng, Xucai Kan, Yong Zhu, Zongyang Zhang, Yue Li, Haiming Tian, Wei Sun, Xiansong Liu
Summary: In this study, Al3+ ion substituted M-type Sr0.7La0.3Fe11.75.x-AlxCo0.25O19 (0 < x < 0.12) hexagonal ferrites were synthesized by solid state reaction. The lattice parameters a and c decreased with the increasing Al3+ content, and a single M-type strontium ferrite was obtained within the Al content range of 0 to 0.08. Scanning electron microscopy images showed hexagonal platelet-like particles, and the size of the magnetic powders was about 2-5 μm. The saturation magnetization (M-s) of the hexaferrite decreased with the increase of x from 0 to 0.12, while coercivity (H-c) of the magnetic powders increased with Al3+ content (x) from 0 to 0.12.
JOURNAL OF SOLID STATE CHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
Swati Verma, Anupinder Singh, Sachin Kumar Godara, Jahangeer Ahmed, Saad M. Alshehri, Supriya A. Patil, Mandeep Singh
Summary: SrZnxZrxFe12-2xO19 samples (with x varying within 0.1-0.4) were prepared successfully via solid state route. The study discusses the structural characteristics, microstructural features, and magnetic properties of the samples. The results indicate that the presence of impurity phases and changes in crystal structure can affect the magnetic behavior and microstructural features of the samples.
MATERIALS CHEMISTRY AND PHYSICS
(2024)
Article
Engineering, Electrical & Electronic
M. M. Hessien, Nader El-Bagoury, M. H. H. Mahmoud, M. Alsawat, Abdullah K. Alanazi, M. M. Rashad
Summary: Lithium ion-substituted hexagonal strontium ferrite powders were successfully fabricated using the tartrate precursor route, with the impact of Li+ content and annealing temperature on phase evolution, microstructure, and magnetic performance monitored. Single-phase hexagonal ferrite was achieved at a Li+ ratio of 0.2, but high Li+ ratios led to the observation of an α-Fe2O3 impurity phase at all studied temperatures.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Engineering, Electrical & Electronic
Max Ho, Srinivas P. M. Nagaraja, Rustu Umut Tok, Aysan Rangchian, Pirouz Kavehpour, Yuanxun Ethan Wang, Rob Candler
Summary: Millimeter-wave components often use magnetic fields to provide unidirectional signal transmission, but face difficulties in miniaturization. Hexaferrite materials are selected for their strong magnetocrystalline anisotropy (MCA) and low conductance, but integrating them with semiconductor substrates is challenging. Additive manufacturing using a composite of strontium hexaferrite particles and photoresist has been developed to overcome this challenge. The 3-D printed composite has demonstrated magnetic anisotropy, and the self-biasing field has been experimentally characterized.
IEEE TRANSACTIONS ON MAGNETICS
(2023)