|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Ultrafine-grained Materials X
||Production of Bulk Nanograined Si by High-pressure Torsion at Various Pressures
||Yoshifumi Ikoma, Terumasa Yamasaki, Katsuhiko Saito, Qixin Guo, Zenji Horita
|On-Site Speaker (Planned)
The production of bulk nanograined semiconductor materials is of great interest because of unique electrical and optical properties associated with quantum effect. When Si was subjected to high-pressure torsion (HPT) under the nominal pressure at 24 GPa, not only grain refinement to nanoscale, but also formation of metastable phases such as body-centered-cubic Si-III and rhombohedral Si-XII were observed in the HPT-processed samples. Furthermore, photoluminescence (PL) in the visible light region was observed from the annealed samples. However, the effect of applied pressure during HPT processing on the formation of metastable phases and optical property has not fully understood. In this study, we investigated the HPT processing of Si at various pressures. No appreciable formation of metastable phase and PL were observed from the samples after processing at ≤ 12 GPa. A broad PL peak was observed from the sample after HPT at 12 GPa and successive annealing at 600 °C.
||Planned: Supplemental Proceedings volume