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研究生:李明育
研究生(外文):LEE, MING-YU
論文名稱:FePd薄膜結構與磁性之研究
論文名稱(外文):Structure and magnetic properties of FePd thin films
指導教授:王昌仁
指導教授(外文):WANG, CHANG-REN
口試委員:王昌仁張晃暐袁輔德申繼陽
口試委員(外文):WANG, CHANG-RENCHANG, HUANG-WEIYUAN, FU-TESHEN, CHI-YANG
口試日期:2019-07-15
學位類別:碩士
校院名稱:東海大學
系所名稱:應用物理學系
學門:自然科學學門
學類:物理學類
論文種類:學術論文
論文出版年:2019
畢業學年度:107
語文別:中文
論文頁數:284
中文關鍵詞:濺鍍法擴散法
外文關鍵詞:FePdsputtering
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面心正方結構的L1o FePd薄膜具有高的磁晶異向性能和大的飽和磁化量及居里溫度還有良好的化學穩定性,故近年來被受許多學者關注並著重在以底層效應、摻雜、成份改變影響及化學沉積提高其磁性之研究。本實驗先以不同濺鍍法並且改變靶距製備30 nm Fe50Pd50薄膜於玻璃基板上,進行不同溫度退火(Ta = 500 - 750 oC),FePd經由退火後皆呈現水平磁異向性。隨著溫度之升高,其結構漸從面心立方轉變為面心四方,因而提高其矯頑磁力,但當溫度提升至750 oC,FePd薄膜從L1o相轉變為fcc結構,導致其矯頑磁力大幅降低。實驗結果顯示當靶距越遠,矯頑磁力隨之提升,且靶距的提高有助於降低序化溫度。此外,脈衝濺鍍法鍍製FePd薄膜在靶距為5 cm時,矯頑磁力較高,可能與初始狀態下所受到壓縮應力較大有關。再者,亦研究了在氮氣下製備FePd薄膜經不同溫度後退火研究其結構與磁性。隨著退火溫度的增加,FePd矯頑磁力有明顯的大幅上升。其矯頑磁力最高值為3.9 kOe,出現在氮氣下以直流濺鍍FePd薄膜經700 oC之退火。由於氮氣鍍製當靶距為5 cm時較與氬氣鍍製矯頑磁力提升100 %。氮氣的鍍製並且調控靶距,降低序化溫度區間較為顯著,使磁性之提升可能與初鍍態壓縮應力較大有關。最後,以非磁性銅膜做為頂層,進行不同溫度下擴散,隨擴散火溫度之提升,可進一步的提升其矯頑磁力,由於銅經擴散後會包覆硬磁性FePd晶粒以致降低晶粒之間交互作用,須以較大的磁場下來翻轉其磁區,因而可大幅提高其矯頑磁力至4.5 kOe。
L10 FePd film with a tetragonal structure has high magnetic crystal anisotropy, large saturation magnetization, Curie temperature and good chemical stability. In recent years, many groups have focused on the enhancement of magnetic properties by underlayer, doping, composition and chemical deposition. In this work, structure and magnetic properties of FePd films prepared by various sputtering methods with various distances between target and substrate, post annealed at various temperatures are systematically studied. FePd films deposited at room temperature followed by a rapid therml annealing exhibits in-plane magnetic anisotropy. The phase transformation from face-centered cubic to face-centered tetragonal with increasing Ta in FePd films enhances its coercivity. Nevertheless, the L10 phase is gradually transformed into fcc phase at higher Ta = 750 oC, improves the coercivity. Besides, longer the distances between target and substrate is, the higher the coercive force is, and the change of the distances between target and substrate is helpful to reduce the oredering temperature. In addition, when the distances between target and substrate is 5 cm, FePd film prepared by pulse sputtering method exhiits higher coercivity, which may be related to the large compression stress of as-deposited film. Furthermore, significant enhancement of coercivity to 3.9 kOe is also found for FePd films at nitrogen atmosphere. Finally, Cu was used as the top layer for diffusion at different temperatures. With the increase of annealing temperature, the coercivity was further increased. Since copper would be coated with hard magnetic FePd grains after diffusion, the interaction between grains is reduced and the magnetic field to reverse the magnetization is increased. As a result, the coercivity is significantly increased to 4.5kOe.
誌謝 i
中文摘要 ii
Abstract iii
目錄 iv
表目錄 xi
圖目錄 xvii
第一章 緒論 1
1.1 前言 1
1.2 FePd之簡介 3
1-2-1 FePd合金之晶體結構 4
1-2-2 序化與非序化 5
1-3文獻回顧 7
1-4研究動機 19
第二章 文獻探討 21
2-1 磁性來源 21
2-1-2 磁性物質分類 22
順磁性 (paramagnetism) 22
鐵磁性 (ferrimagnetism) 23
反鐵磁性 (ferrimagnetism) 23
陶鐵磁性 (ferrimagnetism) 24
2-2磁異向性(magnetic anisotropy) 25
2-2-1磁晶異向性 26
2-2-2形狀異向性 27
2-2-3應力異向性 27
2-2-4交換異向性 27
2-2-5誘導異向性 28
2-3磁區 29
2-4磁滯曲線 31
2-5薄膜沉積原理 33
2-6 磁控濺鍍系統 36
2-6-1 直流磁控濺鍍(DC magnetron sputtering) 36
2-6-2射頻磁控濺鍍(RF magnetron sputtering) 37
2-6-3脈衝直流磁控濺鍍系統 39
第三章 研究方法 41
3-1實驗流程 41
3-2 實驗製備及參數 42
3-2-1實驗材料 42
3-2-2基板清洗流程 43
3-2-3濺鍍流程 44
3-2-4製備薄膜底層以及緩衝層之參數 45
3-3快速升溫退火系統 46
3-4晶體結構分析 47
3-5表面形貌分析 49
3-6磁性量測 51
3-7掃描式電子顯微鏡(SEM)薄膜微結構分析 52
3-8 TEM樣品製備 54
3-9穿透式電子顯微鏡(TEM) 56
3-10成份分析 58
第四章 以不同磁控濺鍍法製備FePd薄膜磁性之研究 59
4-1靶距效應對於以射頻濺鍍法製備的Fe50Pd50薄膜結構與磁性之影響 60
4-1-1靶距5 cm下以射頻濺鍍沉積FePd薄膜經由不同溫度後退火之結構及磁性研究 61
4-1-2靶距10 cm下以射頻濺鍍沉積FePd薄膜經由不同溫度後退火之結構及磁性研究 66
4-1-3靶距12.5 cm下以射頻濺鍍沉積FePd薄膜經由不同溫度後退火之結構及磁性研究 71
4-1-4靶距效應對於射頻磁控濺鍍FePd薄膜綜合探討 77
4-2靶距效應對於以直流濺鍍法製備的Fe50Pd50薄膜結構與磁性之影響 81
4-2-1靶距5 cm下以直流濺鍍沉積FePd薄膜經由不同溫度後退火之結構及磁性研究 82
4-2-2靶距10 cm下以直流濺鍍沉積FePd薄膜經由不同溫度後退火之結構及磁性研究 87
4-2-3靶距12.5 cm下以直流濺鍍沉積FePd薄膜經由不同溫度後退火之結構及磁性研究 92
4-2-4靶距效應對於射頻濺鍍FePd薄膜綜合探討 97
4-3靶距效應對以脈衝直流濺鍍法製備的Fe50Pd50薄膜結構與磁性之影響 103
4-3-1 固定脈衝頻率20 kHz並改變脈衝持續時間(10 – 80%) 104
4-3-2固定脈衝頻率35 kHz並改變脈衝持續時間(10 – 80%) 127
4-3-3固定脈衝頻率50 kHz並改變脈衝持續時間(10 – 80%) 149
第五章 氮氣效應以濺鍍研製FePd薄膜 184
5-1氮氣效應對於以射頻濺鍍法製備的Fe50Pd50薄膜結構與磁性之影響 185
5-1-1 靶距5 cm,在氮氣下以射頻濺鍍沉積FePd薄膜經由不同溫度後退火之結構及磁性研究 186
5-1-2 靶距10 cm下以射頻濺鍍氮氣沉積FePd薄膜經由不同溫度後退火之結構及磁性研究 193
圖5.1.13為氮氣下鍍製Fe50Pd50薄膜經不同溫度後退火之MFM圖。隨著退火溫度增加,磁區隨之增大。 199
5-1-3射頻濺鍍靶距12.5 cm 氮氣下沉積FePd薄膜經由不同退火溫度之結構及磁性影響 200
5-1-4射頻濺鍍氮氣下沉積並改變靶距效應之FePd薄膜結構與磁性之探討 207
5-2氮氣效應對於以直流濺鍍法製備的Fe50Pd50薄膜結構與磁性之影響 219
5-2-1 靶距5 cm,在氮氣下以射頻濺鍍沉積FePd薄膜經由不同溫度後退火之結構及磁性研究 220
5-2-2 靶距10 cm,在氮氣下以射頻濺鍍沉積FePd薄膜經由不同溫度後退火之結構及磁性研究 226
5-2-4射頻濺鍍氮氣下沉積並改變靶距效應之FePd薄膜結構與磁性之探討 239
5-3氮氣效應對於改變靶距沉積FePd薄膜結構與磁性影響之探討。 252
第六章 Cu頂層擴散對FePd結構與磁性影響 254
6-1 Cu頂層擴散效應對經650 oC後退火FePd膜結構及磁性之影響 255
6-1-1結構分析 256
6-1-2磁性之研究 257
6-1-3 表面形貌之研究 261
6-2 Cu頂層擴散效應對經675 oC後退火FePd膜結構及磁性之影響 262
6-2-1結構分析 262
6-2-2磁性之研究 263
6-2-3表面形貌之研究 267
6-3 Cu頂層擴散效應對經700 oC後退火FePd膜結構及磁性之影響 268
6-3-1結構分析 268
6-3-2 磁性之研究 269
6-3-4表面形貌之研究 272
6-4 Cu擴散效應對不同序化FePd薄膜結構與磁性之探討。 273
第七章 結論 276
參考文獻 278


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