As a compound of manganese sulfide is compressed in a diamond anvil cell, it undergoes dramatic transitions. When the overlap is significant enough to make the system metallic, the interaction between the atomic ion and disulfur increases from left to right. Researchers at Universities of Rochester and Nevada, Las Vegas say that transitions from insulator to metal to insulator in diamond anvil cell with unprecedented decreases in resistance, volume across narrow range of pressures at room temperatures, are possible.
Researchers from the University of Rochester and the University of Nevada, Las Vegas say that a compound ofMnS2 can be compressed in a diamond anvil. This is a new type of charge transfer mechanism that is very exciting for the science community. Ashkan Salamat is an associate professor of physics at UNLV.
In a paper flagged as an editor's choice in Physical Review Letters, the researchers describe how MnS2 transitions into a metallic state as the pressure increases. The assistant professor of mechanical engineering and of physics and astronomy at Rochester says that it is highly unlikely that metals can be changed back to an insulator. This material goes from being an insturment to a metal and back to an insturment.
The transitions are accompanied by unprecedented decreases in resistance and volume across an extremely narrow range of pressure change. The metal transition process might eventually be harnessed for technology due to the relatively low temperature. The Dias and Salamat collaboration set new standards for achieving superconductivity at room temperatures.
Their work explores the "remarkably bizarre" ways transition metals and other materials behave when they are compressed in a diamond cell anvil. The new phenomena we are reporting is a fundamental example of responses under high pressure, and will find a place in physics textbooks. There is something intriguing about how sulfur behaves when attached to other elements.
This has led to some amazing discoveries. In order to achieve the breakthrough achieved by the Dias and Salamat labs, the material has to be compressed to the size of a single particle. The way the spin states of individual electrons interact as pressure is applied isUnderlying the transitions described in this paper.
When MnS2 is in its normal insulator state, electrons are mostly in unpaired, high spin orbitals, causing atoms to bounce back and forth. The material has higher resistance to an electrical charge because there is less free space for individual electrons to pass through. As the material is compressed toward a metallic state, the electron orbitals start to see each other, and pairs of electrons start linking up.
This opens up more space for individual electrons to move through the material, so much so that resistance drops dramatically by 8 orders of magnitude, as pressure is increased from 3 gigapascals to 10 gigapascals. The 182 to 268 gigapascals required for superconducting materials is a relative "nudge" compared to this. The drop in resistance of this magnitude is enormous, given the small range of pressure involved.
In the final phase, low resistance is maintained because the electrons remain in a low spin state. New discoveries in basic science often lead to applications that have yet to be explored. A transition metal which can jump from one state to another at room temperature is likely to be useful.
A logic switch or writing hard disk could make a jump from one electronic state to another. New versions of flash memory, or solid state memory, could permutate and take on a new approach using these types of materials. It is possible to drive these materials at 300 kelvin, making them potentially useful for technology.
Dylan Durkee, Nathan Dasenbrock-Gammon, G. Alexander Smith, Dean Smith, Christian Childs, and Simon A. J. A graduate student named Dylan Durkee is the lead author of the book. Other coauthors include Nathan Dasenbrock-Gammon at Rochester, Dean Smith at Argonne National Laboratory, Alexander Smith at UNLV, and Christian Childs at University of Bourgogne. The Department of Energy supported the research.
The UNLV National Supercomputing Institute provided computational resources and some of the work was done at the University of Bourgogne.