Magnetite saturation magnetization

EXAMPLE 18.2. Calculate the saturation magnetization of magnetite, [FejCL]. The lattice parameter of magnetite is about 0.839 nm. 

The saturation magnetization of magnetite is 5.2xl05 Am-1 and the unit cell is of side 837 pm. Assuming the inverse spinel structure, estimate the magnetic moment (in Bohr magnetons) of the Fe2+ ion. [Answers 6.7 fiB and 4 fiB 4.11 B]... 

Harrison RJ, Putnis A (1995) Magnetic properties of the magnetite-spinel solid solution Saturation magnetization and cation distributions. Am Mineral 80 213-221 Harrison RJ, Putnis A (1997) The coupling between magnetic and cation ordering A macroscopic approach. Eur J Mineral 9 1115-1130... 

Fig. 1. Characteristics of PL-Magi nanoparticies typicai for core-sheii magnetic nanoparticies synthesized according to Subheading 3.1 of the protocoi. (a) TEM image. The scaie bar equais 50 nm, and the magnetite core size is of 5-12 nm. (b) Magnetization curve. Saturation magnetization of 34 emu g- or 82 emu (g Fe)-. (c) X-ray diffraction pattern. The average crystaiiite size determined from the broadening of the X-ray diffraction peak is of 10.6 nm...

Sample 4 is a 760-Gauss (0.076-T) fluid consisting of magnetite particles suspended in isopar M. The particles have a median diameter of 9 nm and a bulk saturation magnetization of 0.4 T. 

TABLE 3-1 Size [(d (average) d (standard deviation)], Size Distribution (Ad/d). Saturation Magnetization (Af,), and Residual Magnetization (Mr) for Magnetite Particles at Various Temperatures... 

When the magnetic moment of a magnetite powder or suspension was measured as a reaction product and the time dependence was not a concern, the magnetic moment was measured in the magnetic fields H = 2, 4, 6, 8, 10, 12 and 13K Oe and the measured values were plotted against 1/H and extrapolated to infinite field (1/H = 0) to get the value for the saturation magnetization denoted as. 

We can estimate saturation values of M and B by knowing the crystal structure and lattice parameter of the material and the orientation of the spin magnetic moments. We will illustrate this approach for magnetite. The magnetic moments of each type of ion are summarized in Table 33.7. The Fe ions... 

The mass concentration of the magnetite particles stabilized with sodium oleate in ensemble (Cp o ) was found as a relation of specific saturation magnetization of the stabilized Vf ) and initial particles 3, =... 

The data shown testify that an increase in PEG concentration in the composites causes a decrease in their specific saturation magnetization and lower concentration of magnetite in the composite. Dialysis promotes an increase in magnetite concentration and, accordingly, specific magnetization in the Fc304/Na ol. and Fe304/Na ol./PEG system (Table 10.14). 

Table 10.16 Density (p), Specific Saturation Magnetization Mass Fraction of Magnetite in (mFe304/mcomp) Structure, Saturation Magnetization (Ms), Coercive Force (He), Specific Residual Magnetization M/MsOf the Nanocomposites...

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