- 學位論文
探討Fe40Pd40B20與ZnO在玻璃基板上對低頻磁導率與光電性質之影響
Low-frequency magnetic susceptibility and photoelectric properties of glass/Fe40Pd40B20/ZnO and glass/ZnO/Fe40Pd40B20
摘要
本實驗是使用兩種不同的靶材來製備，分別是直流磁控濺鍍法(Direct Current magnetron sputtering) 製作的Fe40Pd40B20薄膜及射頻磁控濺鍍法 (Ratio Frequency magnetron sputtering) 製作的ZnO薄膜。將此雙層薄膜濺鍍在玻璃基板上，根據以下的沉積條件:(a)Glass/Fe40Pd40B20(XÅ)/ZnO(500Å)和(b)Glass/ZnO(500Å)/Fe40Pd40B20(YÅ)，其中這裡的X及Y分別是25Å、50Å、75Å與100Å。藉由改變Fe40Pd40B20薄膜的濺鍍膜厚及順序，分別使用變頻磁導分析儀(XacQuan)探討其對低頻交流導磁率 (Alternating-current magnetic susceptibility, χac)之影響、最大相位角(θmax)及最大χac值所對應的最佳共振頻率(fres)，再利用四點探針薄膜電阻量測儀(Four Point Sheet Resistivity)測量電阻率(ρ)，最後以微型光譜分析儀(Spectra Smart)量測穿透率及反射率的百分比。由實驗結果顯示，Glass/Fe40Pd40B20(XÅ)/ZnO(500Å)會優於Glass/ZnO(500Å)/Fe40Pd40B20(YÅ)，可能是因為奈米級的Fe40Pd40B20薄膜做為基底時，會誘導奈米晶的磁異向性且增加ZnO的結晶，進而提高其磁性和電性之性能。由X-ray繞射分析儀(X-ray diffractometer, XRD)繞射分析圖可得知，在2θ約34º皆有明顯的ZnO(002)繞射峰，且Fe40Pd40B20(XÅ)/ZnO(500Å)系統的繞射峰值是高於ZnO(500Å)/Fe40Pd40B20(YÅ)系統。使用剖面穿隧式電子顯微鏡 (X-Transmission Electron Microscopy, X-TEM) 的比較，由Fe40Pd40B20(100Å)/ZnO(500Å)的結果顯示，其質地會誘導奈米晶的磁異向性，產生最大的χac值為0.79，在頻率(fres)為10Hz且最大相位角(θmax)為179º。而當Fe40Pd40B20的厚度增加電阻值會減小，可能是因為薄膜表面的晶界產生電子散射效應所致，而Fe40Pd40B20(XÅ)/ZnO(500Å)系統的電阻值皆低於ZnO(500Å)/Fe40Pd40B20(YÅ)系統，推斷也是因為較強的ZnO結晶和Fe40Pd40B20奈米晶結構，會藉由膜層表面的晶界提高其電子散射。此外，關於Fe40Pd40B20(XÅ)/ZnO(500Å)系統和ZnO(500Å)/ Fe40Pd40B20(YÅ)系統之光的穿透率及反射率，當Fe40Pd40B20的膜厚增加，穿透率會逐漸下降，而反射率會提高，也符合穿透率和反射率是成反比的關係。 最後，總結Fe40Pd40B20(XÅ)/ZnO(500Å)系統的磁性和光電性質會優於ZnO(500Å)/Fe40Pd40B20(YÅ)系統，由於緻密的Fe40Pd40B20奈米晶結構和較強的ZnO結晶，這使得Glass/Fe40Pd40B20(XÅ)/ZnO(500Å)用於磁性和光電應用中特別有效。
關鍵字
none並列摘要
The following conditions are deposited : (a) glass/Fe40Pd40B20(X nm)/ZnO(50 nm) and (b) glass/ZnO(50 nm)/Fe40Pd40B20(Y nm), where each of X and Y is 2.5 nm, 5 nm, 7.5 nm or 10 nm. The sputtering sequence and the thickness of the Fe40Pd40B20 film were varied to investigate their effects on the lowfrequency alternative-current magnetic susceptibility (χac), maximum phase angle (θmax), maximum χac and corresponding optimal resonance frequency (fres), electrical resistivity (ρ), and transmission and reflection percentages. Experimental results reveal that Fe40Pd40B20(X nm)/ZnO(50 nm) is better than ZnO(50 nm)/Fe40Pd40B20(Y nm) because the nanocrystallization Fe40Pd40B20 at the bottom of the material can improve its magneto nanocrystalline anisotropy and increase the crystallization of ZnO, improving its magnetic and electrical properties. X-ray diffraction patterns (XRD) demonstrate that the ZnO(002) peak of Fe40Pd40B20¬(X nm)/ZnO(50 nm) is stronger than that of ZnO(50 nm)/Fe40Pd40B20(Y nm). In particular, a comparison of high-resolution cross-sectional transmission electron microscopic (HR X-TEM) observations of Fe40Pd40B20(10 nm)/ZnO(50 nm) and ZnO(50 nm)/Fe40Pd40B20(10 nm) indicates that the Fe40Pd40B20 texture induces magneto nanocrystalline anisotropy into the nanocrystalline Fe40Pd40B20 layer of Fe40Pd40B20(10 nm)/ZnO(50 nm), yielding the highest χac of around 0.79 with an fres of 10 Hz and an θmax of 179º. Furthermore, ρ is reduced as the thickness of Fe40Pd40B20 increases, because grain boundaries and the surface of thin films scatter electrons, causing thinner films to have greater resistance. The ρ of Fe40Pd40B20(X nm)/ZnO(50 nm) is lower than that of ZnO(50 nm)/Fe40Pd40B20(Y nm) because stronger ZnO crystallization and nanocrystalline Fe40Pd40B20 improve the scattering of electrons by the surface of the films. Finally, with respect to the optical transmittance and reflectance of Fe40Pd40B20(X nm)/ZnO(50 nm) and ZnO(50 nm)/Fe40Pd40B20(Y nm), as the Fe40Pd40B20 thickness increases, the transmittance gradually decreases, because transmittance and reflectance are inversely related to film thickness, increasing reflective efficiency. The results reveal that the magnetic and photoelectric properties of glass/Fe40Pd40B20(X nm)/ZnO(50 nm) are better than those of glass/ZnO(50 nm)/ Fe40Pd40B20(Y nm) owing to the tightly nanocrystalline Fe40Pd40B20 crystallization and stronger ZnO crystallization. Fe40Pd40B20(10 nm)/ZnO(50 nm) is particularly effective for magnetic and photoelectric applications.