Carbothermal reduction에 의한 AlN 세라믹스의 열적·전기적 특성 연구 = Effects of carbothermal reduction on the thermal and electrical conductivities of aluminum nitride ceramics

국문 초록 (Abstract)

본 연구는 carbothermal reduction이 AlN 세라믹스의 열적, 전기적 특성에 미치는 영향에 관한 연구이다. Carbothermal reduction의 결과로 Y2O3가 3, 5 wt% 첨가된 시편에서 DC 비저항이 증가되었다. 임피던스 분광법으로 분석한 결과 입자 저항은 크게 변하지 않은 반면 입계 저항이 증가됨을 알 수 있었다. 이러한 비저항의 변화는 2차상의 발전과도 밀접한 관련이 있었다. 또한 AlN 입자의 전기전도도와 열전도도는 밀접한 관련이 있는 것으로 확인되었다. Y2O3가 3 wt% 첨가된 시편에서 carbothermal reduction 후 열전도도가 증가하였지만 Y2O3 첨가량이 더 많은 시편들과 큰 차이를 보이지 않았다.

목차 (Table of Contents)

• 국문 요지 ··············································································· ⅳ
• Ⅰ. 서론 ···························································································· 1
• Ⅱ. 이론적 배경 ··············································································· 4
• Ⅱ-1. AlN의 역사와 발전 ···························································· 4
• Ⅱ-2. AlN의 결정구조 및 물성 ·················································· 6
• Ⅱ-3. AlN의 열적 특성 ······························································· 9
• Ⅱ-4. AlN의 전기적 특성 ·························································· 11
• Ⅱ-5. 복소 임피던스법 ······························································ 13
• Ⅱ-5-1. 기본 이론 ··································································· 13
• Ⅱ-5-2. 결정립과 입계의 RC값 구하는 법 ·························· 17
• Ⅲ. 실험 방법 ················································································· 24
• Ⅲ-1. 사용원료 및 분말제조 ····················································· 24
• Ⅲ-2. 고온 가압소결 (Hot pressing) ······································ 25
• Ⅲ-3. 결정상 및 미세구조 분석 ················································ 26
• Ⅲ-3-1. 밀도 측정 ···································································· 26
• Ⅲ-3-2. 결정상 분석 ································································ 26
• Ⅲ-3-3. 미세구조 분석 ···························································· 26
• Ⅲ-3-3-1. 주사전자 현미경 (FE-SEM, EDS) ·················· 26
• Ⅲ-3-3-2. 투과전자 현미경 (TEM) ··································· 27
• Ⅲ-3-3-3. 전자탐침 미세분석기 (EPMA) ··························27
• Ⅲ-4. 열전도도 및 전기 전도도 분석 ······································ 28
• Ⅲ-4-1. 전극 (Electrode) ······················································· 28
• Ⅲ-4-2. 체적저항 (DC resistivity) ········································ 28
• Ⅲ-4-3. 복소 임피던스 (Complex Impedance) ················ 29
• Ⅲ-4-4. 열전도도 (Thermal conductivity) ························· 29
• Ⅳ. 결과 및 고찰 ············································································ 32
• Ⅳ-1. 결정상 분석 ······································································ 32
• Ⅳ-2. 전기 전도기구 분석 ························································· 38
• Ⅳ-2-1. DC 저항측정 ······························································ 38
• Ⅳ-2-2. 입내 및 입계의 저항 분석 ········································ 39
• Ⅳ-3. 미세구조 분석 ·································································· 47
• Ⅳ-3-1. SEM 분석 ··································································· 47
• Ⅳ-3-2. TEM 분석 ··································································· 48
• Ⅳ-4. 열전도도 분석 ·································································· 56
• Ⅴ. 토 의 ························································································· 58
• Ⅵ. 결 론 ························································································· 60
• Reference ······················································································ 61
• ABSTRACT ··················································································· 69