Magnetic properties, general

It should be kept in mind that quantum chemical calculations of structures and magnetic properties generally are done for the isolated carbocation without taking into account its environment and media effects such as solvent, site-specific solvation or counterion effects. This is a critical question since NMR spectra of carbocations with a few exceptions are studied in superacid solutions and properties calculated for the gas-phase species are of little relevance if the electronic structure of carbocations is strongly perturbed by solvent effects. Provided that appropriate methods are used,... 

As well documented in the literature, spinels are basically known for its magnetic properties. Generally, high temperature preparation methods (ceramic methods) have... 

In the binary Ni—Fe system, = 0 at about 76 wt%Ni and kg = 0 at about 81 wt%Ni. Small additions of Cu lower the Ni content for which A,g = 0 while Mo additions increase the Ni content for K = 0. Thus different alloy compositions around 78 wt% Ni are available which have optimal soft magnetic properties. General relations of the effect of alloying elements in Ni—Fe-based alloys on K, kg, and on the permeability have been developed in [3.14,15]. Figure 4.3-11 shows the position of the lines for =0 and A,s = 0 in the dis-... 

The intrinsic properties may be modified by substitution (31). Ba can be fuUy replaced by Sr or Pb and partly by Ca (<40 mol %). CaM, stabilized with 0.03 mol % La202, is also possible. The intrinsic properties of these M-ferrites vary somewhat and other factors such as sintering behavior and price of raw materials often dictate the commercial viabiUty. Large-scale production is concentrated on BaM and SrM. High quaUty magnets are generally based on SrM, and somewhat lower priced magnets are based on BaM. 

The hysteresis loop, ia general, suppHes information about the magnetic properties such as Af, Af, preferred direction of the magnetisation or... 

From the applications of Ni Mossbauer spectroscopy in solid-state research, it is clear that (1) information from isomer shift studies is generally not very reliable because of the smallness of the observed isomer shifts and the necessity of SOD shift corrections which turn out to be difficult, and (2) useful information about magnetic properties and site symmetry is obtained from spectra reflecting magnetic and/or quadrupolar interactions. 

The number of metal wheels and, more generally, polynuclear cage complexes of the 3d metals has increased considerably in the last decade because of their magnetic properties, especially their behavior... 

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