The impact of ageing on the magnetic properties of Cu(OH)_2 nanoribbons

摘要

We report a comparative study of structural, morphological and magnetic properties of freshly prepared and aged Cu(OH)_2 nanoribbons. Microscopy studies, performed with a transmission electron microscope, a scanning electron microscope and an atomic force microscope, demonstrate that the average length of the Cu(OH)_2 nanoribbons decreases with ageing. The basic Cu(OH)_2 structure is, however, still preserved at this stage, as confirmed by x-ray diffraction measurements. Morphological changes are reflected also in the magnetic properties. For instance, we found that Cu(OH)_2 nanoribbons with ageing gradually lose their one-dimensional antiferromagnetic character as the defects, which form during the ageing process, tend to cut the Cu-(OH)_2-Cu chains into increasingly shorter segments. These defects in aged samples completely change the spectrum of magnetic excitations and make aged samples much more three-dimensional from the point of view of magnetism.