Anisotropy magnetocrystalline

The anisotropy constants K, K2,. .. are defined for cubic lattices, such as Fe and Ni, by expressing the free energy of the crystal anisotropy per unit volume as 

In practice it can be important to know not only the room temperature value of the magnetocrystalline anisotropy constants Ki but also their temperature dependence, which is shown for Fe in Fig. 4.3-3b. For many technical considerations it suffices to take the dominating anisotropy constant Ki into account. 

Curie temperatures and intrinsic magnetic properties at room temperature 

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The direction of the alignment of magnetic moments within a magnetic domain is related to the axes of the crystal lattice by crystalline electric fields and spin-orbit interaction of transition-metal t5 -ions (24). The dependency is given by the magnetocrystalline anisotropy energy expression for a cubic lattice (33) ... 

Fig. 4. The effect of temperature for Mng 6 Zng 3 Fe Fe on (a) initial magnetic permeabiUty, )J., measured on a polycrystalline toroid appHed as a core for a coil driven by a low (B <0.1 mT) ampHtude, low (10 kHz) frequency sinusoidal signal and (b) magnetocrystalline anisotropy constant, measured on a monocrystalline sphere showing the anisotropy/compensation temperature Tq and the Curie temperature, T. To convert joules to calories, divide by...

Iron—Aluminum and Iron—Aluminum—Silicon Alloys. The influence of aluminum on the physical and magnetic properties of iron is similar to that of silicon, ie, stabilization of the bcc phase, increased resistivity, decreased ductility, and decreased saturation magnetization, magnetocrystalline anisotropy, and magnetostriction. Whereas Si—Ee alloys are well estabHshed for electrical appHcations, the aluminum—iron alloys have not been studied commercially. However, small (up to ca 0.3%) amounts of A1 have been added to the nonoriented grades of siHcon steel, because the decrease in ductiHty is less with A1 than with Si. 

The barium ferrite was found to have an increase in magnetic anisotropy, as in the nickel ferrite, but its overall effect on magnetization was less because of greater magnetocrystalline anisotropy. The shock modification caused reduced crystallite size and local damage that resulted in increased microwave absorption. 

The spin-orbit interaction is also called spin-orbit effect or spin-orbit coupling, which is one cause of magnetocrystalline anisotropy. SOC, the intrinsic interaction between a particle spin and its motion, is responsible for various important phenomena, ranging from atomic fine structure to topological condensed matter physics. SOC plays a major role in many important condensed matter phenomena and applications, including spin and anomalous Hall effects, topological insulators, spintronics, spin quantum computation, and so on. 

Magnetization unit, 23 870 Magnet market, 14 645 Magnetocrystalline anisotropy, in ferrites, 11 62-64... 

Magnetocrystalline anisotropy constant, of M-type ferrites, 11 67, 68 Magnetohydrodynamic (MHD) convection, in microfluidic mixers, 26 967 Magnetohydrodynamic power generation, cesium application, 5 704 Magnetometers, SQUID, 23 871... 

Magnetization, in chemisorption of benzene on metal surfaces, 23 129 Magnetocatalytic effect, 27 23, 26 8 Magnetocrystalline anisotropy, 26 146, 147 Magnetogyric ratio, 42 122 Mahan-Nozi6res-De Dominicis theory, 34 ... 

With decreasing particle size, the magnetic contributions from the surface will eventually become more important than those from the bulk of the particle, and hence surface anisotropy energy will dominate over the magnetocrystalline anisotropy and magnetostatic energies. A uniaxial anisotropy energy proportional to the particle surface S... 

Fid. 9. Magnetocrystalline anisotropy. K, V and K2V are the energy barriers for two different directions of relaxation. Figure according to Boudart et al. (215). 

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