High-pressure synthesis is a powerful technique in searching for new materials. We have found a large number of functional oxides using this technique. BiNiO3 is a distorted perovskite compound with unusual Bi1/23+Bi1/25+Ni2+O3 valence state. High-pressure neutron diffraction measurements and bond valence sum calculations show that the pressure-induced melting of the charge disproportionated state leads to a simultaneous charge transfer from Ni to Bi, so that the high-pressure phase is metallic Bi3+Ni3+O3. The same inter metallic charge transfer accompanied with 2.6% volume shrinkage is induced by heating Bi0.95La0.05NiO3 at ambient pressure.
Recently, we have succeeded to extend the attainable static pressure to 410 GPa using a diamond anvil cell (DAC). In this article, our recent advances in the ultra-high pressure generation technique of the DAC are reviewed, and the key factors for the high-pressure generation beyond 300 GPa were discussed. In addition, in such extremely high-pressures range, an optical pressure determination method and a direct observation method of the stress-state by the diamond anvil Raman spectroscopy have been presented.
Accumulation of precise experimental data of fluid thermophysical properties is extremely important from both industrial and scientific point of view. In this article we report briefly recent research activities in our laboratory concerning the measurements of thermophysical properties under high pressure, mainly focussing on the development of various instruments and the innovation of an automatic or a remote control system.
Recent progress of the technology of large-scale high pressure apparatus have permitted us to produce synthetic diamond powders in larger quantities at a lower cost. The advances in high-pressure and high-temperature control technique have enabled the commercialization of high-purity large synthetic diamond crystals. In this article, recent advances and future prospects in the high-pressure apparatus technology for synthetic diamonds are described.
The isostatic press has been applied to various usages since the 1980's. In this article, we would like to introduce our warm isostatic press which is widely used for the manufacturing process of multi-layered electronic components such as MLCC or LTCC in particular.
Such as high pressure machine, it has image difficult to use and dangerous in generally, dose not gain in popularity. In particular over 100 MPa, that is the filed of super high-pressure, there were still many researches carried out on the super high-pressure, however there were few products that is commodification in the world. In this paper, developing machine is easy to use the super high-pressure and technology is utilized super high-pressure of the versatility, therefore commodification shows several possible of super high-pressure.
In typical Hot Isostatic Pressing (HIP) equipment, argon is used for its pressure-medium. New demands have been emerging for HIPs which can use other high-pressure mediums, such as nitrogen and oxygen, as the materials being processed and their applications have been diversified. To meet such demands, Kobe Steel has developed new high-pressure equipments, including HIP for nitrogen atmosphere and HIP for oxygen containing atmosphere. In recent years, hydrogen is attracting attention as one of the promising clean energy sources without emission of carbon dioxide. However, there is a problem of insufficient amount of data for designing components exposed to high-pressure hydrogen. For this demand, we recently developed 100 MPa class high hydrogen pressure testing equipment based on our HIP equipment technology.