The magnetization reversal of Ni nanowires was studied by anisotropic magnetoresistance measurements at temperatures between 15 and 300 K. The wires, synthesized by electrodeposition in a nanoporous polycarbonate membrane, are regular cylinders 22 μm long with a diameter of 75 or 35 nm. The nucleation field was measured on individual nanowires as a function of the angle between the applied field and the wire axis. The results are quantitatively analyzed using classical magnetization reversal theories. Measurements of the nucleation field first obtained as a function of temperature evidence an extra uniaxial anisotropy induced by the contraction of the membrane at low temperature. Combining SQUID measurements and x-ray diffractometry at different temperatures, a clear picture of the large magnetoelastic effect was obtained.

This paper deals with the role of epitaxial strain on the structure and electronic transport properties of metastable SmNiO3 layers grown by metal-organic chemical vapor deposition onto SrTiO3 and LaAlO3 substrates. The characterization of these layers is carried out by high resolution x-ray diffraction and four-probe resistivity measurements. It is found that the SmNiO3 phase is stabilized by in-plane compressive strain whereas in-plane tensile strain induces the creation of oxygen vacancies that induces an annihilation of the metal-insulator transition and a huge increase of the resistivity