Origin of Magnetism

What gives rise to magnetism We know that a current flowing through a wire creates a magnetic field around the wire. The magnitude of the field can easily be found by using the circuit form of Ampere s law  

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G. A. Landrum, R. Dronskowki, The orbital origins of magnetism from atoms to molecules to ferromagnetic alloys. Angew. Chem. Int. Ed. 39 (2000) 1560. 

Zijlstra et al. [69] demonstrated that the reaction of (1.5) is reversible at several bars of pressure at ambient temperature. In the following studies on the origin of magnetic coercivity in these new magnets, Phillips laboratories came with the hydride of LaNij, lanthanum-nickel hydride, which reversibly bonded more than six atoms of H per one formula unit (H/M ratio > 1) [70]. 

Hus J, Ech-Chakrouni S, JordanovaD (2002) Origin of magnetic fabric in bricks its implications in archaeomagnetism. Phys Chem Earth27 1319-1331. 

Ya.B. has worked extensively on the problem of the origin of magnetic fields, stars, and galaxies, actively developing the theory of dynamos. These studies (in particular, that of 1956, paper 7) and one written with A. A. Ruzmaikin (1980, paper 8) are related to his research in hydrodynamics and are reviewed in Sections 3 and 12 of this Introduction. But his major field of endeavor is cosmology. 

Figure 5. Physical origin of magnetic anisotropy (a) compass-needle analogy of shape anisotropy and (b-c) magnetocrystalline anisotropy. In (b) and (c), the anisotropy energy is given by the electrostatic repulsion between the tripositive rare-earth ions and the negative crystal-field charges.

Stohr J (1999) Exploring the microscopic origin of magnetic anisotropies with X-ray magnetic circular dichroism (XMDC) spectroscopy. J Magn Magn Mater 200 470-497... 

To understand the origin of magnetism in Mn- and Cr-doped GaN, we have performed extensive theoretical calculations on (Ga,Mn)N and (Ga,Cr)N systems from zero-dimensional clusters to one-dimensional nanowires, nanotubes, and nanoholes two-dimensional surfaces and... 

To have some insight into the origin of magnetic ordering, it is instructive briefly to analyse the most simple system two atoms a and b, with one electron each, close enough to give rise to electron interaction. Electron wave functions for the interacting system can be expressed as... 

Finally, the physical properties that have attracted the most attention are the great variety of magnetic properties exhibited by the rare earths. The origin of magnetism in these elements lies in their electronic structure. The rare earths, as mentioned earlier, are characterized by partially filled 4/ levels, and it is the detailed manner in which these 4/ levels are occupied that deter-... 

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