Powder ferromagnetic

As an example, 400 g of powdered ferromagnetic nickel flake, cleaned by extraction with chloroform and alcoholic alkali, was suspended in 4124 g H,0 containing 71 g NajSO, and sodium silicate equivalent to 120 g SiO and 37.5 g Na O and heated to 95 C. Over a period of 3.5 hr 0.67 N H2SO4 was added to the well agitated mixture, and the pH dropped from 11.0 to 9.87. The metal powder contained 8.13% silica as a continuous film, corresponding to a 26% yield of silica. When compacted at 70,000 psi the billet had a resistance of more than 30 megohms, as compared to 30 ohms for the untreated powder. Also, the coated powder was much less readily attacked by nitric acid. 

The EGD curve traces the variations on the DTA curve. Because of the pressure sharing of the carrier gas, COj, the endothermic peak with a shoulder at 560, 590 °C shifts to the high-temperature side, in contrast to Figure 13.26. The residue is a black powder, ferromagnetic yield, 70.29%. 

Technology of obtaining nanosized ferromagnetic powders and on their basis with metals-admixtures of Ag, Pt, Au, Cu, Zn was developed for the first time [1]. 

Mechanism of action of nanosized (0.005 - 0.02 p.m) powders of ferromagnetics on biological systems is based on effect of magnetic fields created by ferromagnetic microcrystal assemblies and on specific action of every metal added which determined the field of practical application. 

Powder diagrams of polymetalates, 19 248 [PPh4][Cd(TIPT)3], 40 446-447 (PPhJLMnCrCox),], ferromagnetic ordering, 43 229-230... 

PuP amongst compounds of metallic character, plutonium pnictides PuP, PuAs, PuSb are ferromagnetic. PuP has been studied not only by the magnetization technique but also by neutron diffraction specific heat and Powder polarized neutron... 

The density of CoNi powder decreases steadily in the 8.5-7.5 g cm-3 range as the mean particle size decreases from 300 to 50 nm. The saturation magnetization follows the same trend. It has been inferred from those measurements that the particles are formed by a metallic, ferromagnetic, nonporous core whose density is close to the bulk value (8.9 g cm-3). This core is coated by an impurity layer whose density and thickness are 4 g cm-3 and 2 nm, respectively.33... 

Magnetic Susceptibility Measurements. Magnetic susceptibilities were measured by the Faraday method and were accurate to 2%. Samples, usually as powders, were placed in a cylindrical Teflon boat having an internal volume of 0.30 cc. Measurements were made at 2963, 4357, 5724, 7077, and 8243 G, and at temperatures 77°-295°K. It was possible to correct for ferromagnetic impurities from any field dependent effects. 

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