Ferromagnetic nickel

Nickel — (Ni, atomic number 28) is a silvery white metal that melts at 1455 °C. It is hard, malleable, ductile, and ferromagnetic. Nickel is available in many forms including foil, powder, flakes, sheet, wire, mesh, spheres, and rods. Nickel electrodes find extensive use in rechargeable alkaline batteries such as Ni-Zn, Ni-Cd and -> Ni-MH batteries [i]. In these applications, the (simplified) reaction taking place at the Ni electrode is ... 

A few short papers have dealt with the zero-field NMR of small ferromagnetic nickel and cobalt particles. The physical basis of such measurements is more complicated than that of NMR in an applied field, and this is not discussed here. Suffice it to say that for Ni a considerable size-dependent line broadening is found (189), which could possibly be used to investigate the effect of chemisorption on the surface magnetism of such particles. The Co zero-field NMR can distinguish between superparamagnetic, FCC, and hexagonal close packed (HCP) cobalt (190). 

Fig. 15 FESEM micrographs of PVME filled with (a, b) ferroelectric BaTiOs particles, (c, d) ferromagnetic nickel particles and (e, f) ferroelectric poly(vinylidene fluoride). The figures show the filled hydrogel in the swollen state (a, c, d) low temperature,) and shrunken state (b, d, f) high temperature). The bars correspond to (a-d) 1 pm and (e, f) 500 nm. Reprinted from Theiss et al. (2005), p. 2262. Copyright John Wiley Sons Inc. Reproduced with permission...

The studies initiated in Kharkov concern the magnetic field effect upon the mechanical properties of metals and alloys. The results show that at 4 K a constant magnetic field up to 3.2 MA/m does not affect the mechanical properties of para-and diamagnetic metals (Al, Cu) and Fe-Cu-Ni stainless steels, but causes a 10% increase in the yield stress of ferromagnetic nickel... 

P. M. Tedrow, R. Meservey Spin-dependent tunneling into ferromagnetic nickel, Phys. Rev. Lett. 26, 192 (1971)... 

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. 

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