| About this Abstract | 
   
    | Meeting | 2025 TMS Annual Meeting & Exhibition | 
   
    | Symposium | Advances and Discoveries in Non-Equilibrium Driven Nanomaterials and Thin Films | 
   
    | Presentation Title | B-8: Formation of Novel Q-Si Phases by Swift Heavy Ion Irradiation | 
   
    | Author(s) | Siba Sundar  Sahoo, Naveen  Joshi, Sachin  Kadian, Ambuj  Tripathi, Jagdish  Narayan, Roger  Narayan | 
   
    | On-Site Speaker (Planned) | Siba Sundar  Sahoo | 
   
    | Abstract Scope | Q-silicon, a  new allotrope of zinc-blende silicon, was discovered by nanosecond laser annealing, where localized melting and ultrafast quenching allowed us to create atomically distinct structures of Q-phases. This new phase has a higher density (>60%) than crystalline silicon (c-Si) of zinc blende structure and shows robust room temperature ferromagnetism (Tc>400K). In the current work, we have established high energy ion bombardment of a-Si and c-Si can achieve similar quench rates to create Q-Si phases. The study uses ion - solid interaction simulations coupled with atomistic ab initio modeling to study the conversion methodology of a-Si to Q-Si. We carried out Raman spectroscopy to understand the bonding characteristics of the Q-Si, HAADF Z-contrast imaging to validate the densification of a-Si along the tracks. We also used ultrahigh energy resolution monochromated electron energy-loss spectroscopy (EELS) to detect and visualize the energy states near the Fermi level. | 
   
    | Proceedings Inclusion? | Planned: | 
 
    | Keywords | Nanotechnology, Characterization, Thin Films and Interfaces |