Spin transition has attracted the interest of researchers in various fields since the early 1930s, with thousands of examples now recognized, including those in minerals and biomolecules. However, so far the metal centres in which it has been found to occur are almost always octahedral six-coordinate 3d(4) to 3d(7) metals, such as Fe(II). A five-coordinate centre is only rarely seen. Here we re...

In recent years it has become apparent that the performance of detection sensors for land mines and UXO may be seriously hampered by the magnetic behavior of soils. In tropical soils it is common to find large concentrations of iron oxide minerals, which are the predominant cause for soil magnetism. However, a wide range of factors such as parent material, environmental conditions, soil age, an...

We report a "ligand stripping" method for the creation of secondary structures of colloidal nanocrystals. Using iron oxide as an example, we demonstrate that the use of diols as "stripping agents" allows the controllable removal of the original capping ligands and induces aggregation of nanocrystals into well-defined clusters.

The electronic modification of TiO(2) with highly dispersed NiO particles smaller than ca. 2 nm by the chemisorption-calcination-cycle technique has given rise to a high level of visible-light-activity exceeding that of iron oxide-surface modified TiO(2) simultaneously with the UV-light-activity being significantly increased.

In this study, magnetic iron oxide nanoparticles (Fe3O4) with the size range of 20-30 nm were prepared by the modified controlled chemical co-precipitation method from the solution of ferrous/ferric mixed salt-solution in alkaline medium. In this process polyethylene glycol was used as a surfactant to prevent the solution from agglomeration. The prepared magnetic nanoparticles were characterize...

Learning scheme is the key to the utilization of spike-based computation and the emulation of neural/synaptic behaviors toward realization of cognition. The biological observations reveal an integrated spike time- and spike rate-dependent plasticity as a function of presynaptic firing frequency. However, this integrated rate-temporal learning scheme has not been realized on any nano devices. In...

There are not so many examples of real magnetic structures connected with living beings. Nanoparticles composed of magnetic iron oxides have been found in magnetotactic bacteria, some animals and plants. However, majority of structures found in living organisms are diamagnetic. Magnetic techniques used in biosciences and biotechnology are thus predominantly based on magnetic labelling of otherw...

Using iron oxide as catalyst, glycerol can be converted to allyl alcohol through a dehydration and consecutive hydrogen transfer.

A porous Ni-Fe oxide with improved crystallinity has been prepared as a highly efficient electrocatalytic water oxidation catalyst. It has a small overpotential, a low Tafel slope, and an outstanding stability. The remarkably improved electrocatalytic performance is due to the porous structure, high extent homogeneous iron incorporation, ameliorative crystallinity, and the low mass transfer res...