Home > 게시판 > 세미나
아래와 같이 콜로퀴움을 개최하오니 많이 참석해 주시기 바랍니다.
4시 20분부터 제1과학관 31214 e+강의실에서 다과를 준비하오니 많은 참석 부탁드립니다
제목: 액체금속 및 물의 과냉각 현상과 국소구조와의 관계 : 정전기 공중부양 기술 및 dynamic diamond anvil cell
연사: 이 근 우 박사님 (한국표준과학연구원)
일시: 2011년 6월 8(수) 오후4:30
장소: e+첨단강의실 (31214호실)
초록: In this talk, new technologies will be introduced that allow studying extreme physical properties at high temperature and high pressure. The first is electrostatic levitation (ESL) which provides containerless and contactless environment. Using the ESL, we can study physical properties of solids and liquids up to about 4000 oC and achieve deep supercooling, since it removes heterogeneous nucleation site by lifting liquid drop. The high temperature and deep supercooling can not be obtained with normal methods. The second is dynamic diamond anvil cell (dDAC) that is able to modulate a given static pressure with high compression rate, ~ 103 GPa/s. This device has been developed to study intermediate strain rate between static (<10-2 /s) and dynamic pressure (> 104 /s), since dDAC can control freely de/compression rate. This capability has been highly desired in high pressure physics community, because there have been discrepancies between static and dynamic pressure study which should be resolved.
Under containerless environment achieved by ESL, I have studied thermodynamics and structure of liquid metals and alloys with quasicrystals, polytetrahedral crystals, and simple crystals. In particular, the relation of the local order of supercooled/supercompressed liquids and nucleation barrier has been focused since it is important to understand (nano) crystallization, glass transition, material synthesis, and so on. In the present, it will be shown that Frank’s hypothesis, i.e., icosahedral short range order as the local order of liquid metals that has been unsolved for over 50 years, is unambiguously vindicated (PRL 2003, PRB 2005, 2008). In addition, liquid metals can have different local orders depending on electronic properties (PRL 2004, JCP 2007).
On the other hand, supercompressed liquid water transforms metastable ice VII phase in stable ice VI phase with fast compression, but not with slow compression, confirmed by time-resolved microRaman scattering and optical image. Our results show that the supercompressed liquid water has bcc-like order, which supports the local order of high density liquid water suggested by simulation studies (PRB 2006). Additionally, it will be demonstrated that fast compression rate can affect crystal morphology during crystal growth, and molecular dynamics (PNAS 2007). In conclusion, the similarity of local order between liquids and crystals determines the path of phase transformation.
|공지||<12/8(Thu.) 11:00am>노벨상 소개 강연 - 2016년 노벨 물리학상: 위상 응집 물리의 탄생||2016.11.28||1079507|
|606||<Oct. 18(Wed.) 4:30 PM> AlGaN/GaN HEMT 센서플랫폼 (KANCSensGaNTM) 기술 소개||2017.10.11||53696|
|605||<April 25(Mon) 16:30> Neutron Recoil Polarization in Low‐energy Photodisintegration of the Deuteron||2016.04.25||53737|
|604||<6/21(Thu.) ~ 22(Fri.)>Mini-workshop for the entanglement entropy at SKKU||2018.06.18||53991|
|603||<June 1(Wed.) 4:30 PM> 중력으로 강한 핵력 이해하기||2016.05.26||54001|
|602||<May. 18(Wed.) 4:30 PM> Search for Hidden Neutrinos at the High Energy Frontier||2016.05.23||54243|
|601||<Mar. 15(Wed.) 4:30 PM>반도체 Fab Process와 물리학 전공자||2017.03.14||54295|
|600||<Nov. 9(Wed.) 4:30 PM> 20-nm resolution imaging of brain circuitry by next-generation expansion microscopy||2016.11.02||54320|
|599||<Dec. 14(Wed.) 4:30 PM>중력과 양자 얽힘 (tentative)||2016.12.07||54356|
|598||<May. 4(Wed.) 4:30 PM> 플라즈마를 이용한 표면처리 기술||2016.04.27||54547|
|597||<11/23(Fri.) 11:00am>Barrier-bound States in Flat-band Systems||2018.11.19||54592|
|596||<April. 27(Wed.) 4:30 PM> 로봇과 함께 살아갈 미래||2016.04.22||54726|
|595||<11/21(Wed.) 2:00pm>Origin of Hawking Radiation||2018.11.20||55152|
|594||<2/8(Fri) 2:00pm ~ > 5d SCFTs and Type IIB 5-brane webs||2019.02.01||55276|
|593||<June 8(Wed.) 4:30 PM> 세계와 우리나라 우주개발 도전||2016.06.01||55299|
|592||<12/2(Fri.) 14:00>Overview of HIMAC facility||2016.12.01||55552|
|591||<Nov. 2(Wed.) 4:30 PM> 현대 우주론 이론과 관찰 (Theories and observations of modern cosmology)||2016.10.19||55558|
|590||<Mar.24(Wed.)> A tale of quantum magnets||2021.03.18||55691|
|589||<May 10(Wed.) 4:30 PM>Trend and beyond of semiconductor technology (반도체 미세화 및 신기술 동향)||2017.05.04||56160|
|588||<March. 9(Wed.) 4:30 PM>가치 있는 대학 생활이란 무엇인가?||2016.03.07||56220|
|587||학술세미나 개최 안내: Local Modes in Vibrational (and Rotational) Spectroscopy||2015.10.01||56231|