title: High-yield preparation of uniform cobalt hydroxide and oxide nanoplatelets and their characterization.
abstract: Cobalt hydroxide nanoplatelets with a uniform hexagonal shape were prepared in high yield ( approximately 95%) by a facile hydrothermal route in the presence of poly(vinylpyrrolidone). This method provides a simple, low-cost, and large-scale route to produce beta-cobalt hydroxide nanoplatelets with an average diameter of 280 nm and a thickness of ca. 26 nm which show a predominant well-crystalline hexagonal brucite-like phase. Their thermal decomposition produced anisotropic nanoplatelets of cobalt oxides (CoO and Co3O4) under designed temperatures. The products were characterized by transmission electronic microscopy, selected-area electron diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetric, and thermogravimetric analysis. The magnetic properties of the products were investigated by a superconducting quantum interference device magnetometer. Co3O4 nanoplatelets exhibit a superparamagnetic behavior, and they might be a promising material to study the magnetic tunneling effect as anisotropic nanostructures.
authors.affiliation: Department of Chemistry, School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: Yanglong
authors.initials: Y
authors.lastname: Hou
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kondoh
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Shimojo
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Kogure
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Ohta