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Amorphous Co_xGd_1-x nanowire arrays and core-shell-like Co_xGd_1-x/CoO nanowire arrays with composite amorphous and crystalline structures, where 0.75 < x < 0.99, are fabricated successfully by employing electrochemical deposition with the assistance of AAO templates. Based on the experiments, dissolving of the organic salt of Gd in dimethylsulfoxide and the deposition potentials are the critical factors for formation of amorphous structures and different morphologies. Investigation of the magnetic properties shows that Co_xGd_1-x nanowire arrays have superparamagnetic characteristics, and core-shell-like Co_xGd_1-x/CoO nanowire arrays possess better soft ferromagnetic properties. Moreover, these magnetic behaviors are attributed to spin disorder of amorphous structures and shape anisotropy, which arise from the large aspect ratio of one-dimensional nanoscale materials.

We have previously described the enhancement of piezoelectricity in low crystallinity Bi${}_{12}$TiO${}_{20}$–BaTiO₃ (BTO-BT) nanocomposites. This poses a question regarding the effect of the crystallinity on piezoelectricity. Here, the variation of crystallinity and structure that was developed along the temperature gradient was confirmed. The magnitude of the piezoelectric constant was found to have great relationship with the crystallinity and distortion of BiO₅ polyhedra of amorphous Bi${}_{12}$TiO${}_{20}$. The highest piezoelectric constant of 13pC/N was obtained together with the lowest crystallinity and highest degree of distortion of BiO₅ polyhedra. These results highlight the key role of the amorphous phase and further confirm the importance of distortion of BiO₅ polyhedra in influencing the piezoelectricity. In this view, one may also expect that macroscopic polarity could be improved by increasing the amorphous content and the degree distortion of the BiO₅ bonding units in the system.