New research has revealed electronic mechanisms that govern new metal chemical bonding and metavalent bonds (MVBs) in 2D layers of group IV chalcogenides, which can improve energy harvesting and electricity generation.
Finding new materials with unique properties can help advance technology today. Recently, scientists have turned to a group of compounds called group IV chalcogenides that have interesting properties and make them suitable for technological applications. This compound contains elements from group VI of the periodic table combined with elements from groups III to V of the periodic table, such as PbTe, SnTe, and GeTe.
Chalcogenides can reverse the transition between amorphous and crystalline phases in response to changes in temperature, pressure, or electric fields. This unique property is a practical application in rewritable optical discs and electronic memory devices due to the optical response of the two phases.
In addition, these chalcogenides are important in energy harvesting and energy generation due to their high electrical conductivity and efficient conversion of thermal energy into electrical energy through the thermoelectric effect.
A recent study by Professor Umesh Wagmare, Department of Theoretical Sciences, Jawaharlal Nehru Center for Advanced Scientific Research (JNCASR), Bengaluru (an autonomous institution of the Ministry of Science and Technology, Government of India) explored the possibility of introducing newly introduced metavalents. bonding. (MVB) investigate the mechanism and implications for material properties in the 2D layer of Group IV chalcogenides.
This research, published in Angewandte Chemie International Edition and supported by SERB-DST, Government of India and J.C Bose Research Association JNCASR, provides a theoretical analysis of the principles that focuses on the nature of bonding between five different 2D lattices of the group. IV chalcogenide. This category includes compounds that show extraordinary properties, as opposed to the amorphous structure of glass, which transitions to a crystalline form in less than 100 nanoseconds upon heating or cooling.
Based on the idea presented by Professor C. N. R. Rao, this research aims to uncover the electronic mechanism that controls chemical bonding in this material. The results, which took almost two years of theoretical and computational work, revealed the unique properties of this material, challenging the conventional idea of ​​chemical bonding.
Prof. Wagmare: “These materials, known as elemental metals, have a combination of properties that defy conventional understanding. They show electrical conductivity similar to metals, high thermoelectric efficiency typical of semiconductors, and unusually low thermal conductivity, creating three properties that cannot be explained by the conventional concept of chemical bonding .”
A key aspect of this research is the explanation of a new type of chemical bond proposed by Matthias Wuttig in 2018, which is called a metavalent bond. This innovative bonding concept combines the properties of metallic and covalent bonding and offers a new perspective on the unique behavior of this material.
Prof. The theoretical work done by Wagmare and his team has important industrial and promising applications. The chalcogenides investigated in this study have been used in computer flash memory, exploiting their ability to change optical properties during the transition from crystalline to amorphous state. Furthermore, the use of this material in energy storage, especially as a phase change material, paves the way for more sustainable and efficient energy solutions.
In addition, the research is linked to the emerging field of quantum materials, which is in line with the objectives of India’s National Mission on Quantum Technology. With its distinct electronic structure and properties, this material provides a prototypical example of a quantum topological material, an important element in the development of quantum technology.
The research, published in two papers—one focused on three-dimensional materials and the other on metavalent bonds in two-dimensional materials—represents a major leap forward in understanding the chemistry of quantum materials. Prof. Noting the importance of this discovery, Wagmare said, “Traditional chemical bonding does not explain the unique nature of this material. We have discovered quantum material chemistry, which opens new avenues for research.”
