無機鹵素鈣鈦礦/磁性金屬薄膜 -雙層異質結構之形貌、磁性及熱穩定性分析

Abstract

在這項研究中我們主要使用物理氣相沉積法(Physical vapor deposition, PVD)製備鐵鈀合金薄膜，並且利用旋轉塗佈法將鈣鈦礦(CsPbBr3)量子點旋塗於表面，接續觀察樣品在旋塗前後(CsPbBr3/FePd v.s FePd)的變化，包括表面形貌、光學及磁性，並且觀察不同退火溫度(100˚C ~ 180˚C)後的轉變。CsPbBr3/FePd在原子力顯微鏡(AFM)量測下，我們發現表面在經退火後粗糙度大致不變，且平均約為±10 nm高低且誤差值為1.5 nm。從掃描式電子顯微鏡(SEM)發現量子點為平均大小約11 nm的正方形，並且退火180˚C後有融合的現象。透過光致螢光(PL)的數據分析我們得知在退火100˚C後，光訊號強度下降了3/4，且發光波長有紅移4 nm的現象。最後經由磁光柯爾量測從室溫到退火160˚C，FePd樣品的矯頑場增加了74 %，而CsPbBr3/FePd樣品的矯頑場僅增加了19.2 %；由此結果方知CsPbBr3是一個可以保護磁性材料的覆蓋層。

In this study, we used the physical vapor deposition to prepare FePd alloy, and spin-coating to spread perovskite (CsPbBr3) quantum dots (QDS) on the surface. We characterized the surface of the spin-coated perovskite and bave FePd before and after. Various measurements are carried out, including surface morphology, optical and magnetic properties, after thermal annealing the sample from 100˚C to 180˚C. The AFM study shows that the surface roughness of the CsPbBr3/ FePd remained invaricant and the average value was about ± 10 nm. The SEM study shows that the QDS were of square cubic sample with an average size around 11 nm and aggregated after thermal annealing at 180˚C. PL measurement shows that the intensity of perovskite decreases by 75 % after thermal annealing at 100˚C, and there is a red shift in PL-spectram. The magnetic coercivity of CsPbBr3/ FePd was increased by 19 % without serious inter diffusion effect as compared with the pure FePd was increased by 74 % after thermal annealing (100 to 160 ˚C). The perovskite could serve as a good capping layer, and the interface between perovskite and ferromagnetic layer sustained with good thermal stability.