LBNL 한인 모임

Abstract: Grain boundary defectstopological defects around grain boundaries (GB)play an essential role in electrical, optical, magnetic, mechanical, and chemical properties of the polycrystalline materials. When the grain size of the materials decreases to the nanometer scale, the grain boundary defects predominantly determine those properties, opening up a variety of new applications. Although researchers have sought ways to study the contribution of specific grain boundary defects to the properties, non-uniformity in grain size and shape and random misorientation between the grains make these tasks challenging. This presentation will first discuss controlling 3D heteroepitaxy of colloidal faceted nanocrystals to grow uniform multiple grains organized into a well-defined geometry which gives a new opportunity for overcoming such limitations from the non-uniformity and randomness. Within the resulting nanocrystals, we will see that three-dimensionally patterned strain field exist in the form of disclinations and dislocations. We will then discuss how we can apply the 3D hetroepitaxy to investigate the effect of microscopic grain geometry on the macroscopic properties. For example, we can obtain a correlation between the GB defects and the catalytic property, because the patterned strain creates exact GB structure in a periodic fashion that serves as the active sites for catalysis. Lastly, we will highlight that the epitaxy-based design principles can significantly extend the library of grain structures in the nanocrystalline materials.  


Biography: Myounghwan Oh is a postdoc working in Paul Alivisatos group at UC Berkeley and is investigating the properties of the grain boundary defects in the nanocrystalline materials through high-precision control of 3D heteroepitaxy. He received his B.S. in Chemical Biological Engineering from Seoul National University (SNU), Korea, followed by a M.S. in Interdisciplinary of Nanoscience and Technology and a Ph.D. in Chemical Biological Engineering. myoung19.jpg

번호 제목 글쓴이 날짜 조회 수
공지 UKC 2014 Volunteers needed! orppaha 2014.05.28 10848
공지 LBNL 초기 정착 도우미 서비스 (LBNL Initial Settlement Assistance Service) orppaha 2013.08.01 11681
공지 KSEA Berkeley Chapter 소개 orppaha 2013.07.31 10338
공지 LBNL K-Network orppaha 2013.07.31 10510
27 Korea Electrotechnology Research Institute and Berkeley Lab Will Work Together on Smart Grid R&D orppaha 2013.08.07 6388
26 KSEA North West Regional Conference 2013 - Seattle file orppaha 2013.08.14 8602
25 Controlled self-assembly of block copolymer particles from emulsions : Combined study of experiment, theory, and simulation (171016 KSEA Berkeley Chapter Seminar) file 지미버틀러 2019.02.24 1192
24 An Overview of R&D Activities around NST, KISTI and NERSC (171213 KSEA Berkeley Chapter Seminar) file 지미버틀러 2019.04.10 777
23 Designing (photo)electrocatalysts with consideration of its application to real device for hydrogen economy and artificial photosynthesis (180227 KSEA Berkeley Chapter Seminar) file 지미버틀러 2019.04.10 1035
22 Antimony selenide (Sb2Se3) photocathode for photoelectrochemical water splitting (180409 KSEA Berkeley Chapter Seminar) file 지미버틀러 2019.04.10 1676
21 Simulation studies on dynamical and structural properties of liquid state materials: From the perspective of statistical mechanics (180612 KSEA Berkeley Chapter Seminar) file 지미버틀러 2019.04.10 849
20 2018 May Happy Hour file 지미버틀러 2019.04.10 852
19 2018 July Farewell Dinner for Prof. Kim and Prof. Lee file 지미버틀러 2019.04.10 940
18 Development of Innovative materials and process technology: 1. Microreactors for Better Chemical Processes 2. Peptide Self-Assembly (180813 KSEA Berkeley Chapter Seminar) file 지미버틀러 2019.04.10 851
17 2018 Sep. Farewell Lunch for Dr. Kim file 지미버틀러 2019.04.10 1064
» High Symmetry Ordered Multigrain Nanocrystals to Reveal and Maximize the Effect of Grain Boundary Defects (181018 KSEA Berkeley Chapter Seminar) file 지미버틀러 2019.04.11 977
15 Study on the chemical/electronic structures of organic functional materials by combining photoemission spectroscopy with argon gas cluster ion beam sputtering (181214 KSEA Berkeley Chapter Seminar) file 지미버틀러 2019.04.11 912
14 Surface and Interfacial Chemistry of Bio-inspired Phenolic Coatings (190213 KSEA Berkeley Chapter Seminar) file 지미버틀러 2019.04.11 861
13 A single-ion conducting borate network polymer as a viable electrolyte for Li-metal batteries (190410 KSEA Berkeley Chapter Seminar) file 지미버틀러 2019.04.11 887
12 Photo-chemistry and -physics of Ir complexes (190410 KSEA Berkeley Chapter Seminar) file 지미버틀러 2019.04.11 1116