scholarly journals Measurement of effective magnetic anisotropy field and ferromagnetic resonance bandwidth at ferromagnetic resonance frequency in magnetically uniaxial hexagonal ferrites

2019 ◽  
Vol 5 (1) ◽  
pp. 33-39
Author(s):  
Alexey S. Semenov ◽  
Aleksey G. Nalogin ◽  
Sergey V. Shcherbakov ◽  
Alexander V. Myasnikov ◽  
Igor M. Isaev ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Ferromagnetic Resonance ◽  
Transmission Lines ◽  
Anisotropy Field ◽  
Nominal Composition ◽  
Hexagonal Ferrites ◽  
Magnetic Texture ◽  
Measurement Results ◽  
Effective Magnetic Anisotropy ◽  
Ferromagnetic Resonance Frequency

In this work we have considered metrological problems and measurement of magnetic parameters and presented methods of measuring effective magnetic anisotropy field HAeff and ferromagnetic resonance bandwidth ∆H in magnetically uniaxial hexagonal ferrites in the electromagnetic microwave working frequency range. The methods allow measuring HAeff in the 10–23 and 28–40 kE ranges and ∆H in the 0.5–5.0 range. One method (suitable for wavelength measurements in free space in the 3-mm wavelength range) has been implemented for the 78.33–118.1 GHz range. The other method (based on the use of microstrip transmission lines) has been implemented for the 25–67 GHz range. The methods have been tested for polycrystalline specimens of hexagonal barium and strontium ferrites with nominal composition or complex substituted and having high magnetic texture. The measurement results have been compared with those obtained using conventional measurement methods and spherical specimens. Our methods prove to be highly accurate and reliable.

scholarly journals Influence of aluminum substitution on the fi eld of effective magnetic anisotropy and the degree of magnetic texture of anisotropic polycrystalline hexagonal ferrites of barium and strontium for substrates of microstrip devices of microwave electronics

2019 ◽  
Vol 21 (3) ◽  
pp. 166-174
Author(s):  
S. V. Shcherbakov ◽  
A. G. Nalogin ◽  
V. G. Kostishin ◽  
A. A. Alekseev ◽  
E. A. Belokon ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Anisotropy Field ◽  
Ceramic Technology ◽  
Preparation Technology ◽  
Magnetic Texture ◽  
Strontium Hexaferrites ◽  
Barium Hexaferrites ◽  
Microwave Electronics ◽  
Effective Magnetic Anisotropy ◽  
First Time

Abstract. In this paper, the effect of Al3+ ions substitutions on the value of the effective magnetic anisotropy field НАeff and the degree of magnetic texture f of the anisotropic polycrystalline hexagonal barium and strontium ferrites were studied. The samples were obtained by the ceramic technology method and the texture was formed by pressing in a magnetic field. The sample preparation technology presented in detail. The batches of barium hexaferrites were synthesized with the concentration of Al3+ ions: 0.9; 1.4; 2.5 and 2.6 formula units while strontium hexaferrites had Al3+ concentration of 0.1 formula units. It has been shown that by this technology barium and strontium hexaferrites with high value of (in range of 19—35 kOe) and with f = 80—83% could be obtained. The achieved values of НАeff and f could be sufficient for the production of substrates for microstrip microwave devices in millimeter−wave region.For the first time a raise in the degree of magnetic texture of polycrystalline barium hexaferrites with an increase of concentration of Al3+ ions were detected; a slight (5.5—5.8%) magnetic texture of isotropic strontium hexaferrites was also detected. The achieved results discussed in detail. For studied hexaferrites the mechanism of magnetic texture formation during the process of synthesis is proposed.

Large E-field tunability of magnetic anisotropy and ferromagnetic resonance frequency of co-sputtered Fe50Co50-B film

2015 ◽  
Vol 117 (17) ◽  
pp. 17D702 ◽  
Author(s):  
Shandong Li ◽  
Qian Xue ◽  
Honglei Du ◽  
Jie Xu ◽  
Qiang Li ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Resonance Frequency ◽  
Ferromagnetic Resonance ◽  
Ferromagnetic Resonance Frequency

scholarly journals Температурная зависимость эффективного поля магнитной анизотропии и ширины линии ферромагнитного резонанса поликристаллических сложнозамещенных гексагональных магнитноодноосных ферритов в диапазоне частот 25-67 GHz

2020 ◽  
Vol 90 (5) ◽  
pp. 782
Author(s):  
С.В. Щербаков ◽  
А.Г. Налогин ◽  
В.Г. Костишин ◽  
А.С. Семенов ◽  
Н.Е. Адиатулина ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Ferromagnetic Resonance ◽  
Barium Hexaferrite ◽  
Anisotropy Field ◽  
Ceramic Technology ◽  
Strontium Hexaferrite ◽  
Temperature Changes ◽  
Temperature Range ◽  
Resonance Linewidth ◽  
Ferromagnetic Resonance Linewidth

In the work in the frequency range 25 – 67 GHz the temperature changes of the effective magnetic anisotropy field and ferromagnetic resonance linewidth of the samples isotropic and anisotropic hexaferrite SrFe11.2Al0.1Si0.15Ca0.15O19 and anisotropic hexaferrite BaFe10.4Al1.4Si0.15Mn0.1O19 were studied. The samples obtained by ceramic technology with the pressing of the raw blanks in a magnetic field of 10 kOe. The studies were carried out in the temperature range+25 – +85 ºC. It was found that in the specified temperature range, the change in magnetic anisotropy is 9.8 Oe/ºC for barium hexaferrite and 4.2 Oe/ºC for strontium hexaferrite, and the change in ferromagnetic resonance linewidth is 12.2 Oe/ºC for barium hexaferrite and 10 – 12.3 Oe/ºC for strontium hexaferrite.

Random Magnetic Anisotropy and Ferromagnetic Resonance in Nanosrystalline Alloy Fe73.5CuNb3Si13.5B9

2010 ◽  
Vol 168-169 ◽  
pp. 365-368 ◽  
Author(s):  
S.V. Komogortsev ◽  
Rauf S. Iskhakov ◽  
P. Kuznetsov ◽  
A. Belyaeva ◽  
G. Bondarenko ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Ferromagnetic Resonance ◽  
Annealing Temperature ◽  
Anisotropy Field ◽  
Correlation Radius ◽  
Magnetization Curves ◽  
Annealing Conditions ◽  
Random Anisotropy ◽  
Random Magnetic Anisotropy ◽  
Annealing Temperature Dependence

In the paper, we will present experimental results on the Fe73.5CuNb3Si13.5B9 ferromagnetic resonance (FMR) line width as a function of annealing conditions, as well as the annealing-temperature dependence of the crystallite size, coercive force, and the magnetic anisotropy field. We shall show the interrelationship of these quantities, demonstrate that these parameters are all traceable to the nanoparticle crystallization, and indicate how they can be examined by extending the random anisotropy theory. To obtain quantitative parameters of random magnetic anisotropy we investigate the magnetization curves approaching saturation. This technique allows one to quantitatively determine the local magnetic anisotropy field (Ha) and magnetic anisotropy correlation radius (Rc), as well as to estimate the averaged magnetic anisotropy field (<Ha>L) and ferromagnetic correlation radius (RL).

Effect of the Thickness of Cr Interlayer on the High-Frequency Characteristics of FeCoTa/Cr/FeCoTa Multilayers

2011 ◽  
Vol 287-290 ◽  
pp. 1356-1359
Author(s):  
Shan Dong Li ◽  
Feng Xu ◽  
Ming Liu ◽  
Yi Hu ◽  
Jian Peng Wu ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Eddy Current ◽  
High Frequency ◽  
Anisotropy Field ◽  
Eddy Current Loss ◽  
Film Sample ◽  
Current Loss ◽  
Ferromagnetic Layers ◽  
Magnetic Decoupling ◽  
Ferromagnetic Resonance Frequency

The effect of non-ferromagnetic Cr interlayer on the high-frequency ferromagnetic properties (HFFMPs) was investigated by use of FeCoTa/Cr/ FeCoTa triple layered films. In conventional thought, the metal interlayer gives rise to a high eddy current loss and therefore a deteriorated HFFMP. However, it is found that HFFMPs depend on the thickness of Cr interlayer. The HFFPMs are improved by Cr-interlayer with a thickness less than 12 nm (sample C1). Comparing with the Cr-interlayer-free FeCoHf single layered film (sample C0), the magnetic anisotropy field of C1 dramatically increases from 185 Oe for C0 to 558 Oe for C1. As a consequence, a high ferromagnetic resonance frequency over than 3 GHz is achieved for sample C1. When the thickness of Cr-interlayer is more than 120 nm (C2), the HFFMPs are reduced due to the increase of eddy current loss and magnetic decoupling between the ferromagnetic layers.

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