 |
Atomic Resolution Scanning Transmission Electron Microscopy (STEM) Overview
Results of ultra-sensitive atomic resolution X-ray analysis of yttria-added ceramic grain boundaries
Monte Carlo calculations for the theoretical prediction of the stable arrangement of the helium atom grain boundaries
On March 24, 2016, the University of Tokyo and Osaka University announced a new discovery: the yttrium segregation structure of the zirconia ceramic grain boundary has a regular crystal structure at the atomic scale. Zirconia ceramics are solid electrolytes for fuel cells and this discovery may provide a new direction for the development of high-performance ceramic materials.
Different elements such as yttrium (Y) are added to the zirconia ceramic (ZrO2) used for the solid electrolyte to improve the characteristics. Although the addition of yttrium can enhance the ion conductivity inside the crystal, it will concentrate (segregate) at the interface such as the grain boundary and hinder the ion conduction at the grain boundary. Therefore, segregation of different elements in the grain boundary has been considered as a major factor in deteriorating the battery characteristics.
This time, researchers used an atomic resolution scanning transmission electron microscope (STEM) with a resolution of 1 angstrom (10-10m) or less and an ultrasensitive X-ray component analysis method to perform the grain boundary of yttria-added zirconia ceramics. Atomic-scale compositional distribution analysis. The results show that in the range of a few nanometers near the grain boundary, the germanium concentration forms a regular and interlaced regular structure at the atomic scale. According to past views, helium atoms are simply concentrated and do not form a regular structure.
Furthermore, the results of theoretical analysis by atomic-scale Monte Carlo calculations show that this regular structure is very stable under the interaction of grain boundary structures, helium, and oxygen vacancies. This regular structure is very similar to a pyrochlore-type crystal structure that cannot be stabilized in yttria-added zirconia ceramics, and can be considered as a structure formed under the special environment of grain boundaries.
The results of this research have provided basic knowledge for the distribution of different elements added to the ceramics at the atomic scale, such as grain boundaries, as well as the influence on the functional characteristics, and are expected to become the causes of the deterioration of the performance and the implementation of the control policy. . It also shows that by precisely controlling the grain boundary segregation, a new crystal phase can be created that makes the grain boundary alone have other functions. The online version of Nature Communications, a British scientific journal, published this result on March 23 (Japan time). (Special Contributor: Kudosuke)
The present invention provides a multifunctional pull faucet, comprising: a faucet body, a drawing part is provided at the water outlet port thereof, and the drawing part is connected to a main channel, wherein at least three are provided in the faucet body A branch channel, and the three branch channels are all connected to the main channel. A multifunctional pull faucet provided by the present invention, wherein the hot water channel, the cold water channel and the water purification channel (pure water channel) are all connected to the main channel , And the main channel is connected with the drawing part on the main body of the faucet, so that the drawing part can obtain the water quality (hot water, cold water, purified water or pure water) required by different users, thereby improving the user experience, and , By integrating the hot water channel, cold water channel and pure water channel (pure water channel) into the main channel, the internal structure of the faucet is simplified, and the production cost of the faucet is reduced.
Pull Out Faucets,Pull Out Kitchen Tap,Pull Out Sink Faucet,Standard Pull Out Faucet
Yuyao Zelin Sanitary Ware Co., Ltd , https://www.zlsanitaryware.com