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Materials science researchers have reported the discovery of materials that totally defy the laws of chemistry.
In 1954, Linus Pauling was awarded the Nobel Prize in Chemistry for setting a scientific rule regarding the formation of chemical bonds that has held firm for decades. According to his findings, the fragments of the atomic lattice in inorganic materials are connected by ‘vertices’ rather than faces.
This was because Pauling claimed that bonding by faces is so energy-intensive that it simply could not exist in nature. However, new findings published to Nature Communications by an international team of researchers from Russia, Germany, Sweden and the US has found two materials that completely shatter this rule.
The researchers demonstrated these ‘impossible’ modifications to silica coesite-IV and coesite-V, two materials that – according to Pauling’s rule – should not exist. After proving it could be done theoretically using a Russian supercomputer and running subsequent experiments, the team showed it is possible to form binding by faces when the materials are forged in ultra-high pressure conditions.
Within this environment, scientists found that a special modification of silicon oxide, polymorph-coesite, undergoes a number of phase transition at pressure of 30 gigapascals (GPa). This leads to the formation of coesite-IV and coesite-V which maintain tetrahedrons SiO4 as the main structural elements of the crystal lattice.
Taking this further, compressing silicon oxide in a diamond anvil to the pressure of more than 30 GPa and have seen structural changes in this phase using single-crystal x-ray diffraction.
Changes development of materials science
“Two newly discovered coesites contain octahedrons SiO6, that, contrary to Pauling’s rule, are connected through common face, which is the most energy-intensive for a chemical connection,” said Prof Igor Abrikosov, leader of the theoretical research team.
“Our results show that the possible silicate magmas in the lower mantle of the Earth can have complex structures, which makes these magmas more compressible than predicted before.”
This discovery, the researchers said, completely changes the development of modern materials science, showing that fundamentally new clbades of materials exist at extreme conditions. Recreating such conditions in the lab is now one of the most promising ways of creating new materials that could open a whole new range of possibilities for researchers in the field.
Already, in one recent paper, scientists reported on the creation of nitrides that were once thought impossible to obtain. Such discoveries about the structure and mechanical properties of silicon oxide is vital to our understanding of the processes taking place in the mantle of our planet.
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