Shiny example: Did the sun find metal hydrogen?
Over the years, many physicists have claimed that they can convert hydrogen into metals through extremely squeezing-but so far, no one has been able to convince skeptical competitors. Now, French researchers believe they have finally found convincing evidence to prove this transformation. They have created new devices to pressurize and observe small samples of hydrogen. However, others in the field are still skeptical, arguing that the infrared data reported by this French group does not constitute sufficient evidence in itself, but what is needed is conductivity measurement.
Experts have no doubt that hydrogen will turn into metal under high pressure. Theory tells us that pressure liberates electrons from the bondage of single atoms or molecules, allowing them to propagate freely in matter. In fact, many insulators have been observed to undergo this transformation-for example, molecular oxygen proved to be a metal at about 1 million times atmospheric pressure (about 100 GPa) about 20 years ago. Paul Loubeyre, Florent Occelli and Paul Dumas of the French energy agency CEA wrote in a recent paper uploaded to arXiv: "There is no doubt that metal hydrogen should exist."
Metal hydrogen has many amazing properties, including being a superconductor at room temperature. Considering the rich reserves of Jupiter and other gas giant planets, the study of their behavior may also bring new insights into the interior of Jupiter and other gas giant planets.
Very difficult and controversial
But it turns out that the production of metal hydrogen is extremely difficult and controversial. Since its existence was predicted in 1935, researchers have tried to make it in the laboratory by squeezing tiny hydrogen samples at the tips of two diamonds. These micro anvils can release hundreds of gigapascals of pressure, but the results are often ambiguous. In 2016, two researchers at Harvard University reported that the average grade point for manufacturing metal hydrogen is 500. However, others question whether the team has reached such high pressure.
Loubeyre and his colleagues are not new to this research. In 2002, they used visible light to observe the changes in the hydrogen sample. They compressed the hydrogen sample to 320 GPa. When they increased the pressure, they found that the electronic band gap of solid hydrogen decreased proportionally. By extrapolating this line to a higher pressure, they think it should reach zero around 450 GPa. At this time, hydrogen will become a metal, because its electrons will freely enter the conduction band.
To achieve this pressure, the research team developed a new type of "circular" anvil cell in which the sample was squeezed between two tiny planes surrounded by circular depressions. They said that this may generate at least 600 GPa of pressure. They also designed and manufactured an infrared microscope that can be deployed in the intense radiation of the synchrotron source together with a cryostat.
The results show that there is a first-order phase transition between the solid hydrogen of the insulator molecule and the metal hydrogen around 425 GPa
The research team placed a toroidal anvil equipped with hydrogen on a beam line of a solar synchrotron located on the outskirts of Paris. Under a pressure of around 425 GPa, they observed that otherwise the infrared light passing through the sample was almost completely absorbed. They say this proves that the band gap is closed. They added that their results are in good agreement with the predictions of theorists in 2015. They wrote in the paper: "We found that the first-order phase transition rate from the insulator molecule solid hydrogen to metallic hydrogen is close to 425 GPa."
Other researchers welcome this latest study, but some are not completely convinced. Alexander Goncharov of the Carnegie Institution of Science in Washington, said: "I think this paper contains good evidence about the band gap closure of hydrogen." "Some explanations may be incorrect, some data may be better, but I I believe this is effective. Nevertheless, he believes that the evidence is not invulnerable. He believes that although the band gap is small but non-zero, hydrogen may have become a very narrow band gap semiconductor instead of metal.
Mikhail Eremitz of the Max Planck Institute of Chemistry in Mainz, Germany agreed, and argued that the reduction in band gap does not constitute "direct evidence of metallization." He said that what is really needed is to measure the conductivity of hydrogen. He added that he and his colleagues took such a measurement two years ago, and the results showed that the conductivity of hydrogen (just like "semi-metallic") began to conduct at a rate of around 360 GPa, and the conductivity increased with pressure Increase significantly. They also measured Raman spectroscopy to determine whether hydrogen is in a molecular state. "Our data can be complementary to the infrared data of Loubeyre and others," he said, "but (they) completely ignored this work."
The research is described in a paper by arXiv.
Name : REDUCER Vinyl flooring (spc flooring,click spc flooring)
Board Thickness : 4.0-7.0mm
Wearing Layer Thickness :0.3mm,0.5mm as regular
Surface Texture :Deep Grain,Wood Grain,Marble Grain,Stone,Carpet
Finish :UV-Coating
Installation :Click system(Unilin,Valinge)
Delivery Time :15-25 days
Size:6''*48''(150mm*1220mm)
7''*48''(182mm*1220mm)
9''*48''(230mm*1220mm)
9''*60''(230mm*1525mm)
Backing Foam :IXPE(1.0mm,1.5mm,2.0mm) EVA(1.0mm,1.5mm)
Density :2.07kg/m3
Surface :Wood Embossed,Deep Wood Embossed,Handscraped,Eir.
Usage :Bedroom,Kitchen,Basements,Home,School,Hospital,Mall,Commercial to use.
Features :Waterproof,Wear resistant,Anti-slip,Moisture Proof,Fireproof,durable, anti-scratch, anti-bacterail.
Market :Export to American,Canadian,European Market,Part Asia,Africa Countries.Australia Market
Warranty :10 years for commercial and 25 years for residential
Stone Plastic Composite vinyl flooring is more and more popular new style eco-friendly vinyl flooring. SPC rigid flooring is set apart from other types of vinyl flooring by its uniquely resilient core layer. This core is made from a combination of natural limestone powder, polyvinyl chloride and some stabilizers.
SPC vinyl is a luxury vinyl flooring option with a structurally rigid, 100% waterproof core. SPC is also known as rigid core vinyl, and we use these terms interchangeably. Rigid core engineered vinyl flooring is designed to look like wood or stone, but requires less upkeep.
This flooring is durable, waterproof, and perfect for DIY installation. It`s ideal for both home and commercial areas.
REDUCER,PVC REDUCER,SPC REDUCER,WPC REDUCER
JIANGSU PERFECT NEW MATERIAL TECHNOLOGY CO., LTD. , https://www.bffloor.com