서지주요정보
Pt-Co 박막 성장 및 편석 거동에 대한 MEAM (modified embedded atom method) 계산 및 몬테카를로 시뮬레이션과 응용에 관한 연구 = Study on the simulations of the Pt-Co thin film growth and segregation behavior using MEAM (modified embedded atom method) calculations and monte carlo method
서명 / 저자 Pt-Co 박막 성장 및 편석 거동에 대한 MEAM (modified embedded atom method) 계산 및 몬테카를로 시뮬레이션과 응용에 관한 연구 = Study on the simulations of the Pt-Co thin film growth and segregation behavior using MEAM (modified embedded atom method) calculations and monte carlo method / 박성일.
저자명 박성일 ; Park, Sung-Il
발행사항 [대전 : 한국과학기술원, 2001].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8012292

소장위치/청구기호

학술문화관(문화관) 보존서고

DMS 01007

휴대폰 전송

도서상태

이용가능

대출가능

반납예정일

초록정보

This study mainly concerns applications of modeling and simulation for the purpose of playing a fundamental role in the systematic research of required properties materials. The model system is 50%Pt-50%Co binary thin film that is deposited and heat treated. The properties needed are excellent magnetic properties which will make the Pt-Co thin film as a good magnetic recording media. Most requesting conditions of the system's state for the enhanced magnetic properties are the ordered structure and the grain size as small as possible. The disordered structure transformed to ordered state during heating after deposition. However, heating induces grain growth which degrades magnetic properties of materials at the same time. This study explored two possibilities to produce the desired structures for the good magnetic properties. First item was the possibility of forming ordered PtCo film without further heat-treatment. Second item was the possibility of limiting grain growth during heat-treatments. MEAM parameters were obtained through optimizing process with experimentally reported lattice constants and heat of formations of Pt3Co, PtCo and PtCo3. As a test for those parameters calculation of order-disorder transition temperatures of Pt3Co, PtCo and PtCo3, and estimation of composition profiles of PtCo thin films with free surface (111) or (100) was performed. Calculated order-disorder transition temperature were within a range of maximum 120K from experimentally reported values. The forms of composition profiles were coincident to the experimentally reported forms, but segregating element at free surface was predicted to be Pt, which was contrary to the reported experimental result that showed the segregation of component Co at free surface. MEAM parameters were proved to be reliable with regard to Pt-Co atomic mixing behavior and then parameters were used in Monte Carlo simulations. Two kinds of works were performed as followes. First, the uses of pure metal substrates such as Ni, Cu, Au, Al, Ti, Zr, Ru, Pt, Co with free surface planes of (111), (100) or (0001) were investigated using MEAM (Modified Embedded Atom Method) potential energy and Monte Carlo simulation. Through anaysis of atom configurations produced by surface diffusion of Pt and Co atoms on the various pure metal substrates prospects for ordering during film growth were suggested. Ni(100), Cu(100), Au(111), Al(111) and Co(0001) were recommended, but cautions are needed because of oversimplified MEAM parameters for third elements such as Ni, Cu, Au, Ti, Zr, Ru and Al. Second, for the purpose of constructing a base of simulation tool by predicting the exact function of grain growth size to real time, this study searched activation energy which can describe the behavior of mean size development in real time through 2 dimension grain growth simulation using Monte Carlo method. Development of structure in the thin film during deposition and grain growth simulation were also explored using 3-dimension modeling in order to observe the relation between 3-dimensional grain growth and 2-dimensional grain growth. 3-dimensional grain growth simulation showed the development of columnar structure in the thin film and confirmed that grain grew only in directions parallel to free surface, which justified 2-dimensional grain growth simulation of PtCo thin film. Based on this observation 2-dimensional grain growth simulation was performed to estimate optimum activation energy which defines the development scaling of mean size of grains` diameter as real time. Optimum activation energy was estimated as 0.5eV.atom(48.2kJ/mole).

서지기타정보

서지기타정보
청구기호 {DMS 01007
형태사항 vi, 132 p. : 삽도 ; 26 cm
언어 한국어
일반주기 부록 : EAM function fitting and example calculation
저자명의 영문표기 : Sung-Il Park
지도교수의 한글표기 : 이혁모
지도교수의 영문표기 : Hyuck-Mo Lee
학위논문 학위논문(박사) - 한국과학기술원 : 재료공학과,
서지주기 참고문헌 : p. 122-125
주제 Pt-Co 박막
컴퓨터 시뮬레이션
몬테카를로
EAM
입자 성장
편석
Pt-Co thin film
computer simulation
Monte Carlo
Embedded Atom Method
grain growth
segregation
QR CODE qr code