臺灣博碩士論文加值系統

摘要
在本研究中，主要的研究目標是鈷鉑磁性多層膜(鈷的厚度分別為1,0.5,0.4,0.3,0.25,0.2奈米，鉑的厚度為1.0奈米)的結構鑑定。 這些樣品皆在鉑(111)/鉬(110)/藍寶石(11-20)基板與其他特定的基板上。 由於石英測厚儀量測厚度上的不準確，我們結合X光反射率與X光螢光分析來得到正確的鈷鉑多層膜厚度。
X光測量發現鉑(111)可以於鉬(110)緩衝層上面磊晶成長。此外亦發現鉬與鉑之間的水平晶向類似於Nishiyama-Wasserman模型，除了鉑[01-1]方向偏離鉬[001]有0.4度。多層膜中的鉑在水平方向有2至3.5%的壓縮應變而在變化鈷厚度之試樣上的飽和磁化量大致與此應變量呈正比，在變化鉑厚度的試樣上，頑磁場與應變則呈反比。這些實驗呈現出鈷鉑薄膜的雛形。藉此能更了解鈷鉑薄膜結構上的特性，而提昇未來對於鈷鉑薄膜磁性研究的基礎。
在本論文中，建立一套以C語言為基礎的控制系統來透過GBIP控制一套自製的四環繞射儀，並用8254晶片來擷取閃爍偵檢器之X光計數。現在我們已經可以獨立地於本X光實驗室達到X光單晶繞射的實驗。

In this study, the structure determination of the epitaxial [Co(t nm)/Pt(1 nm)]30 magnetic multilayer samples (t=1, 0.5, 0.4, 0.3, 0.25 and 0.2 nm) were aimed. The samples were prepared mainly on Pt(111)/Mo(110)/ Al2O3(11-20) substrates and also certain of different substrates in the MBE chamber. Due to the inaccuracy of quartz monitor in thickness measurement, we combined two other methods ─ the X-ray reflectivity method and the X-ray fluorescence method to obtain the more exact layer thickness in the Co/Pt multilayer.
X-ray measurement have discovered that the Pt(111) can be grown epitaxially on the Mo(110) buffer layer. It was also found that the in-plane orientation relation between Mo and Pt layer closed to the Nishiyama-Wasserman model, but the Pt[01-1] is rotated 0.4°azimuthally from the Mo[001]. The Pt layer in the multilayer has a compressible strain of about 2-3.5% along the in-plane direction. In addition, the saturation magnetization in the samples with different Co layer thickness is roughly proportional to this strain and the coercive force in the samples with different Pt layer thickness is roughly inverse proportional to this strain. These experimental results reveal the generalization of the Co/Pt thin film structure. Consequently, a realization of the Co/Pt structural properties can be upgraded, thereby enhancing the basis for the prospective study of the Co/Pt magnetic properties.
In this thesis, a C-language based control system was designed to control a home-made 4-circles diffractometer via General Purpose Interface Bus(GPIB) and acquire X-ray counts from scintillation counter via 8254 integrated circuit. Now, we can independently achieve x-ray diffraction experiment of single crystal in our X-ray laboratory.

CHAPTER1 INRTODUCTION 1
CHAPTER 2 THEORETICAL BACKGROUND 3
2-1 X-RAY DIFFRACTION 3
2-2 X-RAY REFLECTIVITY ANALYTICAL THEOREM 4
CHAPTER 3 EXPERIMENT 6
3-1 SAMPLE PREPARATION 6
3-2 CHARACTERIZATION OF THE FILM THICKNESS 7
3-3 DIFFRACTOMETER METHOD 9
3-4 CHARACTERIZATION OF THE CRYSTAL ORIENTATION 10
3-5 REFLECTIVITY METHOD 12
3-6 FLUORESCENCE METHOD 12
CHAPTER 4 RESULTS AND DISCUSSION 13
4-1 THE CORRELATION OF Co/Pt MULTILAYERS WITH DIFFERENT THICKNESS OF MULTILAYER Co 13
4-2 THE CORRELATION OF Co/Pt MULTILAYERS WITH DIFFERENT THICKNESS OF MULTILAYER Pt 14
4-3 THE CORRELATION OF Co/Pt MULTILAYERS WITH DIFFERENT THICKNESS OF SEEDING LAYER Pt. 14
4-4 THE CORRELATION OF Co/Pt MULTILAYERS WITH DIFFERENT SUBSTRATES 15
4-5 THE CORRELATION OF Co/Pt MULTILAYERS WITH DIFFERENT SEEDING LAYERS 17
CHAPTER 5 CONCLUSION 19
REFERENCES 20
APPENDICES
1. X-ray reflectivity curve of Co/Pt multilayers with different thickness of multilayer Co.
2 Hardware diagram and software control program of the diffractometer and x-ray intensity measurement.
3 Paper to be appended in physica B (2000/03/01)
TABLE LISTS
Table 3-1 The X-ray reflectivity results and the X-ray fluorescence results of the sample series with different Co thickness.
Table 3-2 Layer thickness determined by X-ray fluorescence and X-ray Reflectivity.
Table 4-1 The determined structure parameters together with magnetic properties as functions of Co thickness.
Table 4-2 The determined structure parameters together with magnetic properties as functions of Pt thickness.
Table 4-3 the determined structure parameters as functions of Pt buffer layer thickness.
Table 4-4 Epitaxial relation of plane normal direction.
Table 4-5 Epitaxial relation of in-plane direction.
FIGURE CAPTIONS
Figure 2-1 Diffraction of X-rays by Atomic Planes in Crystals.
Figure 3-1 Depth profile of the Co/Pt multilayer.
Figure 3-2 Rotation axes of diffractometer method.
Figure 3-3 The reciprocal space definition of the Co/Pt multilayer.
Figure 3-4 (a)In-plan K scan, at H=0,L=0.04 ,(b)Rod scan, at H=0, K=0.688.
Figure 3-5 Typical X-ray fluorescence spectrum.
Figure 4-1 The value of coercivity, Hc as function of the multilayer Co thickness.
Figure 4-2 The saturated magnetization, Ms, function of the multilayer Co.
Figure 4-3 The in-plane strain of multilayer Pt(2 0) as function of the multilayer Co thickness.thickness.

1. L. G. Parratt, Phys. Rev. 95(1954)359
2. R.F.Carcia, J.Appl. Phys., 63, 5066(1988).
3. W.B.Zeper, F.J.A.M.Greidanus, P.F.Carcia, and C.R.Fincher, J.Appl. Phys., 65, 4971(1989).
4. K.Babcook, V.B.Elings, J.Shi, D.D.Awschalom, and M.Dugas, Appl. Phys. Lett., 69, 705 (1966).
5. C.J.Lin and G.L.Gorman, Appl. Phys. Lett., 61, 1600 (1992).
6. C.L.Canedy, X.W.Li and G. Xiao, J. Appl. Phys. 81, 5367 (1997).
7. A.Yamaguchi, S.Ogu, W.H.Soe and R.Yamamoto, Appl. Phys. Lett., 62, 1020 (1993).
8. N.Nakajima, T.Koide, T.Shidara, H.Miyauchi, H.Fukutani, A.Fujimori, K.Iio, T.Katayama, M.Nyvlt, and Y.Suzuki, Phys. Rev.Lett., 81, 5229(1998).
9. J.Thiele, C.Boeglin, K.Hricovini and F.Chevrier, Phys. Rev. B53, 11935(1996).
10. N. Sato, J.Appl. Phys., 61, 1979 (1987).
11. M. Galeotti, A.Atrei, U.Bardi, B.Cortigiani, G. Rovida and M. Torrini, Surf. Sci.,297, 202(1993).
12. H.Bulou, A.Barbier, J.Thiele, R.Belkhou, C.Guillot, B.Carriereand J.P.Deville, J.Mag.Mag. Mater. 148, 13(1995).
13. H.Bulou, A.Barbier, G.Renaud, B.Carriere, R.Baudoing-Savois and J.P.Deville, Surf. Sci., 277-279, 90 (1997).
14. J.C.A.Huang, L.C.Wu, A.C.Hsu, Y.M.Hu, T.H.Wu and C.H.Lee, Phys. Rev., B59 (1998) 1209.
15. J.C.A.Huang, L.C.Wu and C.H.Lee, J. Appl. Phys., B59,1209(1998).
16. L.C.Wu, Master thesis, National Cheng-Kung University (1998).
17. P. Y. Cheng Master thesis, National Tsing Hua University (1999)