The Bonding Nature and Low-Dimensional Magnetic Properties of Layered Mixed Cu(II)-Ni(II) Hydroxy Double Salts

Abstract

Layered mixed metal hydroxy double salts (HDS) with the formulas (Cu0.75Ni0.25)2(OH)3NO3 ((Cu, Ni)-HDS) and Cu2(OH)3NO3 ((Cu, Cu)-HDS) were prepared via slow hydrolysis reactions of CuO with Ni(NO3)2 and Cu(NO3)2, respectively. The crystal structures, morphologies, bonding natures, and magnetic properties of (Cu, Ni)-HDS and (Cu, Cu)-HDS were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transformation infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and a superconducting quantum interference device (SQUID). Even though (Cu, Ni)-HDS has a similar layered structure to that of (Cu, Cu)-HDS, the bonding nature of (Cu, Ni)-HDS is slightly different from that of (Cu, Cu)-HDS. Therefore, the magnetic properties of (Cu, Ni)-HDS are significantly different from those of (Cu, Cu)-HDS. The origin of the abnormal magnetic properties of (Cu, Ni)-HDS can be explained in terms of the bonding natures of the interlayer and intralayer structures.