MAGNETIC EFFECTS ON STRUCTURAL, ELASTIC AND SURFACE-PROPERTIES OF THE3D FERROMAGNETS

Assuming saturated ferromagnetism, the anomalous crystal structures of the magnetic 3d transition elements Fe, Co and Ni can be explained fr om simple band filling arguments. The exceptional elastic properties o f Fe and Co are well described by full potential linear muffin-tin orb ital (FP-LMTO) electronic structure calculations using the local densi ty approximation for the electron density functional, Analysis shows t hat the behaviour of the tetragonal shear constant C' can be understoo d from the contribution of the partially filled spin down band, wherea s the electrons in the almost filled spin up band only play a minor ro le. This strong reduction in the number of electrons which contribute to the elastic properties explains the anomalous behaviour. The surfac e magnetism of the 3d metals was studied by means of a Green's functio n technique within the tight-binding linear muffin-tin orbital (TB-LMT O) method. It was found that the anomalous surface energies of the 3d transition metals can be explained in terms of itinerant surface magne tism. For some of the magnetic metals an unusual property is found, na mely that the lowest surface energy is not connected to the most dense ly packed surface.