Intrinsic Magnetic Properties

5 Magnetic and Electronic Features 7.5.1 Intrinsic Magnetic Properties 

On the other hand, the magnetic properties of LiFeP04 samples may be different in presence of impurities. The case is illustrated by the sample named sample A in Fig. 7.10, with a magnetization curve that deviates strongly from a linear behavior at low fields. This curvature is the signature of ferrimagnetic impurities [10, 109, 114] under the form of nano-sized clusters. In this case, the magnetization M H) is the superposition of two contributions  

The intrinsic part, XmH, is linear in the applied magnetic H and is just the contribution of pure LiFeP04. The extrinsic component that is easily saturated in /7 is the contribution of the ferrimagnetic nanoclusters, which can be estimated in a simple superparamagnetic model [10]. It can be written under the form  

The results we have reported for two impurities, namely y-FeaOs and Fe2P illustrates the necessity of adjusting the synthesis parameters in order to obtain pure samples free of any impurity, and insuring a strict control of the structural quality of the materials. Several physical methods were utilized to analyze the local structure and the electronic properties of the phospho-olivine framework [115]. The quality control of the product is the key to obtain high-performing LFP Li-ion batteries. 

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Substitution for Fe has a drastic effect on intrinsic magnetic properties. Partial substitution by or decreases J) without affecting seriously, resulting in larger and values. Substitution by Ti and Co causes a considerable decrease in K , the uniaxial anisotropy (if j > 0) may even change into planar anisotropy (if < 0). Intermediate magnetic stmctures are also possible. For example, preferred directions on a conical surface around the i -axis are observed for substitution (72). For a few substitutions the value is increased whereas the J) value is hardly affected, eg, substitution of Fe byRu (73) or by Fe compensated by at Ba-sites (65). 

Intrinsically conducting polymers, 13 540 Intrinsic bioremediation, 3 767 defined, 3 759t Intrinsic detectors, 22 180 Intrinsic fiber-optic sensors, 11 148 Intrinsic magnetic properties, of M-type ferrites, 11 67-68 Intrinsic photoconductors, 19 138 Intrinsic rate expressions, 21 341 Intrinsic semiconductors, 22 235-236 energy gap at room temperature, 5 596t Intrinsic strength, of vitreous silica, 22 428 Intrinsic-type detectors, cooling, 19 136 Intrinsic viscosity (TV), of thermoplastics, 10 178... 

Primary intermediates, 9 265-266 Primary intrinsic magnetic properties, of M-type ferrites, 11 67-68 Primary ions, backscattered, 24 106 Primary irritancy toxicology studies, 25 218... 

Secondary intrinsic magnetic properties, of M-type ferrites, 11 67, 68 Secondary ion mass spectroscopy (SIMS), 24 74. See also SIMS entries archaeological materials, 5 744 Secondary ions, measurement of, 24 107 Secondary lead, 14 756-760 developments related to, 14 760 Secondary mercury production, end-uses and sources for, 16 39-42 Secondary metabolites... 

Sm2Fei7(iso-structural to S1112C017) there are three octahedral interstitial sites which may be filled by nitrogen atoms to form Sm2Fei7N3. The effect of interstitial atoms on the intrinsic magnetic properties of iron-based intermetallics can be further exploited in materials design. 

Numerical micromagnetics, which may be based either on the finite difference or finite element method, resolve the local arrangement of the magnetization which arises from the interaction between intrinsic magnetic properties such as the magnetocrystalline anisotropy and the physical and chemical microstructure of the material. The numerical solution of the equation of motion also provides information on how the magnetization evolves in time. The time and space resolution of numerical micromagnetic simulations is in the order of nanometers and nanoseconds, respectively. 

The intrinsic magnetic properties of the Er2Fei4B intermetallic compound have been previously investigated [1], According to the literature data [1,2] the magnetic ordering temperature of this compound is Tc = 554 K. Er2Fei4B exhibits one successive spin reorientation transition (SRT) at about 325 - 327 K. 

Coey J.M.D., Hong Sun, Hurley D.P.F. (1991) Intrinsic magnetic properties of new rare-earth iron intermetallic series. J. Magn.Magn.Mater. 101, 310-316. 

The size of the domains largely determines the ultimate bit density that can be obtained by means of the writing procedures described in the previous section. The size of the written domain does not depend exclusively on the cross-section of the focussed laser beam since it also depends in a complicated way on the temperature, the external field and the intrinsic magnetic properties of the magnetic film. It will be shown that the domain will collapse when the external field is too high, while it will become distorted from circular symmetry when the external field is too low. It is also of much importance whether the magnetic domain, after having been written... 

Curie temperatures and intrinsic magnetic properties at room temperature... 

The physical basis of the use of Fe— Si alloys, commonly called silicon steels, as soft magnetic materials is the fact that both the magnetocrystalline anisotropy isTi and the magnetostriction parameters >.100 and Xm of Fe approach zero with increasing Si content (see Fig. 4.3-5a). The lower the magnitude of these two intrinsic magnetic properties is, the lower are the coercivity He and the AC magnetic losses The total losses ppe consist of the static hysteresis losses p y and the dynamic eddy current losses pw which may be subdivided into a classical p c and an anomalous p eddy current loss term. 

Of all known magnetic materials, Fe—Co alloys with about 35 wt% Co have the highest saturation polarization Is = 2.4 T at room temperature and the highest Curie temperature of nearly 950 °C. The intrinsic magnetic properties Is,Tc,Ki, and khki as a function of Co content are shown in Fig. 4.3-16. 

Depending on their base metal they exhibit characteristic differences of technical significance. Accordingly they are classified into three groups Fe-based alloys, Co-based alloys, and Ni-based alloys. The characteristic variation of their intrinsic magnetic properties saturation polarization Is, saturation magnetostriction A.S, and the maximum field induced magnetic... 

Magnetic materials based on the Fe—Co—V alloy system were the first ductile magnets. The intrinsic magnetic properties may be found in [3.6] while extensive magnetic materials data are treated in [3.56]. The optimum magnetic behavior is obtained for alloy compositions around Fe-55 wt% Co-10 wt% V. As the isothermal sections of the Fe—Co—V phase diagram Fig. 4.3-56a and Fig. 4.3-56b show, this alloy is mainly in the fee y-phase (austenite) state at 900 °C,... 

Table4.3-42 C05RE alloys. Room temperature intrinsic magnetic properties, the crystal anisotropy constant K, the magnetic saturation Ms, the anisotropy field = 2K /Ms, and the Curie temperature, [3.10]...

Table 4.3-43 Room temperature intrinsic magnetic properties, of C017RE2 alloys [3.10] ...

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