An international team of scientists, which included a professor at St. Petersburg State University Sergei Krivovichev, found that known from the middle of the twentieth century Stepanovite and Zhemchuzhnikovite Yakut minerals are natural analogues of polymers, artificially created in the 1990s. Results of the study, which changes the perception by scientists of skeletal structures widely used in organometallic chemistry and pharmacology, are presented in a scientific article «Minerals with metal-organic framework structures», published by the prestigious Science Advances.
Stepanovite and Zhemchuzhnikovite minerales were discovered in Yakutia in the middle of the XX century and named after famous geologists Pavel Ivanovich Stepanov and Yuri Apollonovich Zhemchuzhnikova. Soviet scientists have found the formula of these minerals, but their structure was up to date unknown. The problem decoding it engaged many scientists. Professor of St. Petersburg State University Sergei Krivovichev and chief scientific researcher of the Department of Mineralogy, Moscow State University professor of Russian Academy of Sciences Igor Pekov were success to resolve the problem in 2016.
In parallel, the study of these minerals chemists engaged Tomislav Frishchich and Igor Haskich from McGill University (McGill University). Exploring metal-organic frameworks (MOF), they suggested that a number of interesting MOFcontaining compounds may have natural counterparts - Stepanovite and Zhemchuzhnikovite. They synthesized these minerals in the laboratory and deciphered the structure, and when they learned that scientists in Russia received some data on natural samples as well, offered them to continue working together.
The result of the study was a unique discovery - MOFs are not the invention of man. MOF, at least in the form of rare minerals existed on Earth long before the have been designed by chemists. First found in nature MOF-containing crystals were Stepanovite and Zhemchuzhnikovite, but researchers do not rule out that the similar "synthetic minerals" can be found not only in Siberia.
"Stepanovite and Zhemchuzhnikovite - are interesting organic minerals, which seems to balance on the border of geosphere and biosphere. Chemists are well aware that the metal-organic frameworks and coordination polymers are one of the most promising areas of modern inorganic chemistry. And our work has shown that they are associated with mineralogy! In fact, this is a fundamental discovery, an interdisciplinary crossroads of two sciences ", - Sergey Krivovichev said.
St. Petersburg State University professor noted that the study allowed the scientists to ensure the possibility of the materials which have always been considered as absolutely artificial to form up in nature. "It turned out that the principles of self-assembly of new structures used today in laboratory conditions act in nature as well and, therefore, can lead to very interesting discoveries in the field of coordination polymers mineralogy ", - said Sergey Krivovichev.
The scientific staff of the department of non-ferrous metals and gold of the National Research Technological University "MISA" led by senior researcher Sergey Gudoshnikov created a new type of permanent magnets preserving powerful magnetic properties at extreme temperatures. This is for the first time in Russia that such magnets have been developed.
Active development of the Far North and the Arctics involves the development of special instrumentation, taking into account the harsh natural conditions of the region. Permanent magnets is one of the most important instrumental components in transportation systems, automation, electrical engineering, aerospace vehicles. Their functional properties depend on the maximum working temperature, above or below which they can be demagnetized.
Researchers of the National Research Technological University "MISiS" succeeded in creating a high quality strong permanent magnet alloy based on NdFeB (neodymium-iron-boron), which is 30% lighter and smaller than existing foreign and domestic counterparts. Supermagnet also able to work at extreme temperatures and withstand temperature oscillations.
Due to the fact that the composition of the alloy contains praseodymium rare earth metal in a large percentage, unique manufacturing techniques and new corrosion resistant coating, the supermagnet can operate effeciently in t civil and military engines at temperatures ranging from -180 ° C to + 150 ° C.
When you create a new type of magnet domestic raw materials are used, which could serve as a basis to start import substituting production.
"The innovative wet-pressing in an inert freon environment has significantly reduced losses on the oxidation of magnetic materials in the manufacturing process and with high accuracy to maintain their predetermined chemical and phase composition, required for the implementation of maximum magnetic characteristics" - development project manager, PhD in Physics and Mathematics Sciences Sergei Gudoshnikov says.
The relatively small size of the magnet and its relative ease of use are especially important in the aerospace industry. Since the rise of one kilogram of cargo into orbit costs about 20 thousand dollars, these properties make supermagnet indispensable for applications in appliances and electronics - from engines to navigation systems. Along with this,
new magnet is characterized by high reliability and by possibility to be produced without taking energy from external sources.
The prototype created by the scientific team of the Department of Nonferrous Metals and Gold National Research and Technology "MISA" University of products will be presented at the international military-technical forum "Army 2016" in September 2016.