Ferromagnetic material

TaMe 7.6. Properties of ferromagnetic elements Chemical element Curie temperature (TJK) 

TaMe 7.7. Properties of selected ferromagnetic compounds Ferromagnetic compound Curie temperature (TJK) 

Ferrite type Chemical formula Structure type, crystal system, lattice parameters, strukturbericht, Pearson symbol, and space group Magnetic induction saturation (B/T) Curie U (T,rc) 

Cobalt ferrite CoFejO, Spinel type, cubic H11, cF56 (Z = 8) Fd3m 0.53 520 

The fabrication and investigation of magnetic nanomaterials started much earlier than their electric analogs. The magnetic films had been fabricated in the middle of previous century and immediately after an attention has been drawn to the difference 

2 The Peculiar Physical Properties of Nanosized Ferroics (Nanoferroics) 

Iron oxide nanoparticles with average sizes 2-8 nm have been studied in [60] by X-ray diffraction, TEM and magnetization measurements. It follows from Fig. 2.33 that magnetization of larger particles saturates more easily than that of smaller 

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Building and testing of probes for an optimal coating control of ferromagnetic materials. 

The experimental tests have validated the theoretical model for eylindrical products in non ferromagnetic material, therefore with a long solenoid ... 

The eddy current method allows to evalute the state of stress in ferromagnetic material. The given method is used for determining own stress as well as that formed in effect of outside load. With regard to physical principles of own stress analysis, the dependence between the magnetic permeability and the distance between atomic surfaces is utilized. 

Equation (A2.5.20) is the Curie-Weiss law, and the temperature at which the magnetic susceptibility becomes infinite, is the Curie temperature. Below this temperature the substance shows spontaneous magnetization and is ferromagnetic. Nonnally the Curie temperature lies between 1 and 10 K. However, typical ferromagnetic materials like iron have very much larger values for quantum-mechanical reasons that will not be pursued here. 

Ferroin complexes Ferromagnetic materials Ferromagnetism Ferromagnets Ferromanganese... 

J. L. Snoek, New Developments in Ferromagnetic Materials, Elseviei, Amsteidam, the Netbedands, 1947. 

The mixed valent oxide Mn.O occurs in nature as the mineral hasumannite. The stmcture of this ferromagnetic material has been the subject of much dispute. Mn.O is the most stable of the manganese oxides, and is formed when any of the other oxides or hydroxides are heated in air above 940—1000°C. The oxidation of aqueous solutions of Mn (OH)2 can also lead to the formation of Mn O. ... 

Ferromagnetic materials are differentiated from those that ate nonferromagnetic by the permeabdity ]1 as defined by the foUowing ... 

Erequencies from 1 kHz to 50 MHz are used for various appHcations (3). Ferromagnetic materials have a skin-effect response to eddy currents which restricts the penetration depth. Nonferromagnetic materials on the other hand can be inspected to greater depth. In 6061-T6 aluminum, for example, a cod having a 1-kHz frequency effectively penetrates the surface to a depth of 3.2 mm (1). The same probe in steel penetrates to a depth of 0.5... 

Eor steel and other ferromagnetic materials, property deterrnination is more difficult. Other tests are made to measure the continuity of protective metallic coatings. Residual stresses induced in welded stmctures and in components in service owing to chemical attack may contribute to early failure. 

Mag netic Tapes. Chromium dioxide, Cr02, is used as a ferromagnetic material in high fidelity magnetic tapes (qv). Chromium dioxide has several technical advantages over the magnetic iron oxides generally used (58,246). 

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