本研究使用超高真空電子束蒸鍍磊晶生長[Fe 14 Å /Pd19 Å]5與[Fe 3 Å /Pd 4 Å]5於加熱的MgO(100)基板。在400 oC生長[Fe14 Å /Pd19 Å]5，由成分分析可知薄膜上半部仍呈現層狀結構顯示交互混合並不均勻且生長溫度為600 oC時，FePd薄膜始呈現垂直磁異向性。當[Fe 3 Å /Pd 4 Å]5生長溫度為400 oC，薄膜具有[001]方位之L10 FePd顯示交互混合確實有提升，同時薄膜已具垂直異向性且垂直矯頑場(Hc,)為17504.7 Oe。當生長溫度提升為600 oC與700 oC，Hc,逐步提高為34007.0與600015.5 Oe。但700 oC製備樣品經後退火700 oC持溫5小時處理，Hc,大幅下降至110011.9 Oe。經退火處理的樣品的L10序化比例(0.94)大於700 oC製備的FePd薄膜的0.71，且Hc,與Ku間並無顯著關係，因此Ku與L10序化比例對於FePd薄膜Hc,有較小的影響。在生長溫度為400 oC、700 oC與700 oC後退火處理，FePd薄膜為島狀結構且晶界皆由MgO(基板)所組成，同時FePd晶粒尺寸約略相同 (~15-17 nm)，因此導入晶界與晶粒尺寸對於Hc,影響可被排除。由理論計算，當異質磊晶生長的FePd薄膜厚度大於22 Å時，薄膜可經由應力鬆弛生成缺陷(如差排)降低應變。由穿透式電子顯微鏡缺陷分析，疊差密度(ρS.F.)與Hc,伴隨生長溫度的提高而增加且ρS.F.提高時Hc,也隨之提升；當生長溫度為700 oC時，ρS.F.為1.050.04 nm-2，經後退火處理後降為0.510.06 nm-2。由ρS.F.與Hc,的擬和分析，Hc,是正比於〖ρ 〗_(S.F.)^1.5證實強栓固作用，因此磁化翻轉時薄膜應力鬆弛誘發的疊差扮演磁區壁的強栓固位置，造成磁區壁移動阻力提升進而增加Hc,。由高角度環形暗場影像分析發現700 oC生長之FePd薄膜中有一本質疊差，其兩端邊界係由一對1/2<110>部分差排組成，顯示高溫生長的薄膜中晶格不匹配產生之全差排可由爬升分解機制提高ρS.F.，造成ρS.F. 隨著生長溫度提高而提升。經後退火處理，由於1/6[112 ̅]與1/3[111]部分差排的滑移與相互反應造成ρS.F.的下降，使得Hc,減少。由於疊差係磁區壁強栓固位置，藉由調控[Fe 3 Å/Pd 4 Å]5薄膜生長速率可改變ρS.F.與Hc,。在低的生長速率(0.005 Å/s)時，由於部分差排間相互作用機會的增加近似於薄膜經後退火處理，導致Hc,下降至1400±12.0 Oe；由於差排爬升分解的過程需要時間，因此高生長速率(0.03 Å/s)抑制了差排爬升分解與ρS.F.，使得Hc,降為1920±7.3 Oe。(最高的矯頑場是在中等的生長速率生成)
為了降低序化溫度，嘗試添加Cu3N以及N2於FePd薄膜並進行後退火處裡。當添加可熱分解的Cu3N層於蒸鍍製備之FePd薄膜([Fe 3 Å/Pd 4 Å]4/Cu3N (15 Å)/[Fe 3 Å/Pd 4 Å])再進行後退火600 oC持溫20分鐘，薄膜為L10 FePdCu結構且經高角度環形暗場影像分析得知Cu傾向佔據原本Fe的晶格位置，減弱了Fe和Pd spin-orbital耦合，造成磁晶異向性下降且呈現軟鐵磁性。於濺鍍製備之[Fe 8 Å /Pd 4 Å]8中添加N2，當添加N2或提高N2比例並經400 oC後退火處理1h，薄膜為(111)方位fcc FePd且晶粒尺寸有顯著的提升，顯示氮氣脫離產生的空位可提升相互擴散與晶粒成長，但粒徑3-8 nm之fcc FePd接近L10 FePd最小熱穩定尺寸(~5 nm)，使得薄膜呈軟鐵磁性。

In this study, [Fe 14 Å /Pd19 Å]5 and [Fe 3 Å /Pd 4 Å]5 thin films were grown at elevated temperatures by an ultra-high vacuum electron beam deposition on MgO (100) substrates. When [Fe14 Å /Pd19 Å]5 was prepared at 400 oC, the upper part of thin film remains layer structure indicating the intermixing phenomenon is not uniform through the elemental mapping analysis, and [Fe14 Å /Pd19 Å]5 film exhibits magnetic perpendicular anisotropy until the grown temperature is 600 oC. As [Fe 3 Å /Pd 4 Å]5 was prepared at 400 oC, [001] L10 FePd with perpendicular anisotropy and out-of-plane coercivity (Hc,) of 17504.7 Oe is obtained implying the intermixing phenomenon is improved. As, the prepared temperatures of [Fe 3 Å /Pd 4 Å]5 are 600 oC and 700 oC, the Hc, are 34007.0 and 600015.5Oe, respectively. One of the FePd films prepared at 700 oC was then post annealed at 700 oC for 5 hs, but Hc, drops apparently to 110011.9 Oe. As [Fe 3 Å /Pd 4 Å]5 prepared at 700 oC with and without post annealed, the L10 ratio are 0.94 and 0.71, respectively. In addition, Ku have less relevance to Hc, in FePd films. This results indicate both L10 ratio and Ku have less dependence on Hc, of FePd film here. FePd thin films are island structure and the grain boundary is composed of MgO (substrate), and average grain sizes were about 15-17 nm indicating similar grain sizes as prepared at 400 and 700 oC with or without post-annealing, respectively. Therefore, the effects of grain size and grain boundary can be rule out. Defects such as dislocation and stacking fault will be generated to reduce the mismatch strain during the growth process as thickness is about ~22 Å. According to the defect density analyzed by transimission electron microscopy, the stacking fault densities (ρS.F.) are closely related to Hc,, in addition Hc, and ρS.F. are increased as growth temperature raising. And, the ρS.F. are 1.050.04 nm-2 and 0.510.06 nm-2 as prepared at 700 oC treated without or with post annealing, respectively. Hc, is proportional to 〖ρ 〗_(S.F.)^1.5, indicating the strong pinning effect, therefore, stacking faults act as domain wall strong pinning sites and it will increase the resistance of magnetic domain wall motion during magnetization reversal, resulting in higher Hc,. By high angle annular dark field analysis, an intrinsic stacking fault was found and its bounded is composed of a pair of 1/2 <110> partial dislocations as FePd film prepared at 700 oC, showing total dislocation can be dissociated into stacking fault via climbing dissociation mechanism. Therefore, ρS.F. increase as growth temperature rising. As a FePd film was treated with post annealing, ρS.F. significantly decreases by 1/6 [112 ̅] and 1/3 [111] partial dislocations reacting with each other, leading to less strong pinning sites and lower Hc,. Because stacking faults acting as strong pinning sites, ρS.F. and Hc,can be manipulated via adjusting growth rate of [Fe 3 Å/Pd 4 Å]5 films. At lower growth rate (0.005 Å/s), the opportunity of partial dislocation interaction in FePd flm was raised, which is similar to FePd film treated post annealing, leading to lower Hc, (1400±12.0 Oe). Besides, it takes some time for dislocation dissociation by climbing, therefore, higher growth rate (0.03 Å/s) reduces climbing dissociation and ρS.F., causing lower Hc, (1920±7.3 Oe). (Therefore, an optimum value of Hc,exists at the moderate growth rate)
To reducing ordering temperature, adding Cu3N layer or N2 in FePd film and then treated with post annealing are also studied. When adding thermal dissociated Cu3N layer to FePd film, which was prepared by electron beam deposition([Fe 3 Å/Pd 4 Å]4/Cu3N (15 Å)/ [Fe 3 Å/Pd 4 Å]) and treated post annealing for 20 min, L10 FePdCu phase is obtained. By high angle annular dark field analysis, Cu atom tends to occupy the Fe lattice site, therefore, the spin-orbital coupling between Fe and Pd is reduced, leading to soft magnetic behavior. [Fe 8 Å /Pd 4 Å]8 films with some nitrogen were prepared via sputtering and then treated with post annealing at 400 oC for 1 h. And, (111) oriented fcc FePd film with larger grain size is obtained as adding N2 or raising N2 ratio, indicating the addition of nitrogen can promote atomic inter-diffusion. But, FePd films with grain size about 3-8 nm are similar to the smallest thermal stable size (~5 nm) of L10 FePd, resulting in soft magnetic behavior.

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