Magnetic solid solutions

Substrates are non-magnetic solid solutions of rare-earth garnets with Ca ", Mg " and Zr " ions. By varying the composition, almost any lattice parameter in the range 12.290-12.620 A can be obtained (Mateika, Laurien Rusche, 1982). 

Four of the solid solutions of Table III have excess entropies of solution which include contributions from magnetic disordering in both the alloy and in one or both of the pure components. These contributions can be quite large, and since there is no assurance... 

In further studies along this line. Greenwood et al. have examined the magnetic superexchange interactions in the solid solution series La cCai cRu03 (0 < x... 

The magnetic properties of the new solid solution series SrFe Rui 3 3, (0 < X < 0.5) with distorted perovskite structure, where iron substitutes exclusively as Fe(in) thereby causing oxygen deficiency, has also been studied by Greenwood s group [147] using both u and Fe Mossbauer spectroscopy. Iron substitution was found to have little effect on the magnetic behavior of Ru(IV) provided that X remains small (x < 0.2). 

Amorphous NiP alloys with > 10% P (generally obtained by deposition from acidic electrolytes) are non-magnetic (see [66] and references therein), as required of the underlayer for thin-film media. Although the structure of these alloys is generally assumed to be a solid solution of P in Ni, a recent report [67] has suggested that NiP with 7.4-10% P deposited from acid sulfate electrolytes is better represented by a microcrystalline structure composed of 4-5 nm fee NiP solid-solution grains. 

Thus the combined magnetic and esr data may be interpreted as showing Mn(Cp)2 to possess a high-spin 62+ ground state in various organic solvents or in solid solution in... 

Six [Ln(Pc)2] complexes with heavy lanthanide ions (Ln = Tb, Dy, Ho, Er, Tm or Yb) were investigated by the measurements of alternating current (AC) magnetic susceptibility [18]. Out of the six compounds, [TbPc2] and [DyPc2] were found to show temperature and frequency dependence on AC magnetic susceptibility similar to that observed for the transition-metal SMMs, while the rest did not. Their SMM behaviour have been observed either in bulk, in dilute solid solutions... 

By forming solid solutions between two ferrites, it is possible to tune the properties magnetically. An example is provided by the solid solution Zn,Ni1 xFe204, which is between the normal spinel ZnFe2C>4 and the inverse spinel NiFe2C>4. Reaction to form a solid solution with NiFe2C>4 ... 

In this way and by numerical evaluation, Driessens (2) proved that the experimental activities could be explained on the basis of substitutional disorder, according to Equation (27), within the limits of experimental error. It seems, therefore, that measurements of distribution coefficients and the resulting activities calculated by the method of Kirgintsev and Trushnikova (16) do not distinguish between the regular character of solid solutions and the possibility of substitional disorder. However, the latter can be discerned by X-ray or neutron diffraction or by NMR or magnetic measurements. It can be shown that substitutional disorder always results in negative values of the interaction parameter W due to the fact that... 

Oxides and Sulphides. The influence of annealing temperature and quenching in air on the structural and magnetic properties of the solid solution, (CuFe2-04)0 2( o.5 2 5 4)0.2( 20Jo.6 Studied. Annealing at 1300 °C... 

The basic question is how to perform extrapolations so as to obtain a consistent set of values, taking into account various complications such as the potential presence of mechanical instability. Additional complications arise for elements which have a magnetic component in their Gibbs energy, as this gives rise to a markedly non-linear contribution with temperature. This chapter will concern itself with various aspects of these problems and also how to estimate the thermodynamic properties of metastable solid solutions and compound phases, where similar problems arise when it is impossible to obtain data by experimental methods. 

The oxide film formed in dry air at room temperature consists of a spinel phase, probably a solid solution of magnetite and maghemite. Such films form on magnetic tapes. They are around 1.5-2.0 nm thick, and in a dry atmosphere, can provide indefinite protection (e.g. the Delhi pillar). Ali and Wood (1969) found that with time and at a relative humidity of 46%, some hematite developed as well. At higher temperatures (200-300 °C) well defined duplex films with an inner layer of magnetite... 

Trivalent Solutes. It has proven difficult to find a trivalent cation that substitutes exclusively for Fca ions over a complete solid-solution range. However, Dehe et al." have compared Mossbauer, neutron-diffiaction, and saturation magnetization data to arrive at the following formulations ... 

Ni and Co are immiscible elements with Ag or Cu. Especially Ag is not miscible with Ni or Co even in liquid state. Therefore, there were no previous attempts to make Raney Ni or Co with dissolved Ag and no studies on their catalytic properties, ffere, we will show an approach to make Raney Ni or Co with Cu or Ag. In the case of Al-Co-Cu system precursor, MA was an effective process to prepare a supersaturated single solid solution as shown in Fig.9 (11). The crystallographic structure after leaching of this specimen showed a broad fee phase and no other phases were observed. To examine the as-leached state, the variation of magnetization was measured with the temperature (12). Figure 10 shows the result. The magnetization... 

In the case of Al-Co-Ag, rapid solidification was effective to make a supersaturated solid solution (13). In this system, the magnetization also increased with increase of temperature and the diffraction lines of fee Co appeared upon annealing at 1073K for 3.8ks as shown in Fig. 11 (14). 

Energy losses in soft magnetic materials arise due to both hysteresis and eddy currents, as described in the previous section. Eddy current losses can be reduced by increasing the electrical resistivity of the magnetic material. This is one reason why solid-solution iron-silicon alloys ( 4% Si) are used at power frequencies of around 60 Hz and why iron-nickel alloys are used at audio frequencies. Some magnetically soft ferrites (see Section 6.2.2.1) are very nearly electrical insulators and are thus immune to eddy current losses. Some common soft magnetic materials and their properties are listed in Table 6.19. Soft magnetic alloys are described further in Section 6.2.1.6. 

When a series of solid solutions between Cu and Ni is formed, it is observed that the spontaneous magnetization decreases linearly with increasing Cu content until no spontaneous magnetization remains at 60 at % Cu (see Figure 6.58). At this composition, we have added about 0.54 electrons to the d band and about 0.06 electron to the band. But the 0.54 electron added to the d band in Figure 6.57 will fill both d subbands, and the magnetization will be zero. The 10.6 total valence electrons per atom are now equally divided between spin up and spin down, as shown in Figure 6.59. 

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