Catalysis significantly affects our way of life. Catalysis plays an important role in many biological and technological processes. For example, the world’s food supply is based on a famous catalytic process – the Haber Bosch process, that converts hydrogen and nitrogen into ammoniac which is then used as the central ingredient for fertilizers. Gaining improved understanding of catalysis at the fundamental level of atomic orbitals, chemical interactions, energetics and symmetry is a very active field in chemistry.
The elements carbon and nitrogen are generally unreactive. Therefore, reactive precursors like ammonia are usually employed for C–N bond-formation in organic synthesis. Surprisingly, MPI scientists were able to synthesize CCN3– – a quasi organic molecular anion searched for since decades – using elemental C and N. The anion is stabilized in the bulk host framework of the nitridometalate Ba5[TaN4][C2N]. The reactivity of CCN3– might be of use in organic synthesis.
Sanjay Singh has been working as a group leader in the Solid State Chemistry department of Prof. Claudia Felser. He has joined as an assistant professor in the School of Materials Science and Technology at the Indian Institute of technology (IIT-BHU), Varanasi, India. He will be actively collaborating with Prof. Claudia Felser and his colleagues in MPI-CPfS.
Binghai Yan has been working as a group leader in the solid-state chemistry department of Prof. Claudia Felser since 2012. In Feb 2017 he is appointed as an assistant professor in the department of condensed matter physics, Weizmann Institute of Science, Israel. In the new institute, he will continue his theoretical research on emerging topological materials, not least in cooperation with the Felser group.
Emilia Morosan is a professor of Physics and Astronomy, Chemistry, and Materials Science and Nanoengineering at Rice University. Her research focuses on the design and synthesis of new compounds with unconventional electronic and magnetic ground states, with particular interest in superconductivity, local and itinerant electron magnetism, heavy fermions, quantum phase transitions and more.
A Weyl semimetal is a topologically non-trivial phase of matter that hosts mass-less Weyl fermions, particles that remained elusive for more than 80 years since their theoretical prediction by the German mathematical physicist Hermann Weyl in 1929, but discovered experimentally only in 2015.
Finely tuning modern materials can lead to dramatic changes: With uniaxial strain we achieved a topological change of the electronic structure in the unconventional superconductor Sr2RuO4. At the same time its transition temperature is more than doubled and results under applied fields yield more information about the nature of the superconductivity in this material.
Scientists from the Max Plank Institute for Chemical Physics of Solids in Dresden have explored the electronic structure of LaBi and have observed the existence of three Dirac cones: two that coexist at the corner and one at the center of its Brillouin zone. Thus, they have unambiguously proven the topological character of LaBi.
Compounds with the MgAgAs crystal structure (half-Heusler phases) represent an important class of compounds in modern materials science. Knowledge of all possible element combinations is of basic importance. By means of a knowledge-based extension of the pure high-throughput computational chemistry method, previously unknown phases in the MgAgAs type were predicted on the basis of a refined chemical bonding model and experimentally verified.