화학용액 증착법으로 제조한 Bi0.9A0.1Fe0.975V0.025O3+α (A=Nd, Tb) 박막의 구조와 전기적 특성 = Microstructural and Electrical Properties of Bi0.9A0.1Fe0.975V0.025O3+α (A=Nd, Tb) Thin Films by Chemical Solution Deposition Method

다국어 초록 (Multilingual Abstract)

We have evaluated the ferroelectric and electrical properties of pure BiFeO3 (BFO) and Bi0.9A0.1Fe0.975V0.025O3+α(A=Nd, Tb) thin films on Pt(111)/Ti/SiO2/Si(100) substrates by using a chemical solution deposition method.
The remnant polarization (2Pr) of the Bi0.9Tb0.1Fe0.975V0.025O3+α (BTFVO) thin film was approximately 65 μC/cm2,with a maximum applied electric field of 950 kV/cm and a frequency of 10 kHz, where as that of theBi0.9Nd0.1Fe0.975V0.025O3+α (BNFVO) thin film was approximately 37 μC/cm2 with a maximum applied electric field of910 kV/cm. The leakage current density of the co-doped BNFVO thin film was four orders of magnitude lowerthan that of the pure BFO thin film, at 2.75×10-7 A/cm2 with an applied electric field of 100 kV/cm. The grainsize and uniformity of the co-doped BNFVO and BTFVO thin films were improved, in comparison to the pureBFO thin film, through structural modificationsdue to the co-doping with Nd and Tb.

국문 초록 (Abstract)

화학 용액 증착법으로 순수한 BiFeO3 (BFO) 박막과 Bi0.9Nd0.1Fe0.975V0.025O3+α(BNFVO), Bi0.9Tb0.1Fe0.975V0.025O3+α (BTFVO) 박막을 Pt(111)/Ti/SiO2/Si(100) 기판 위에 증착하였다. Nd, Tb와 V을 동시 도핑된 BNFVO 박막과 BTFVO 박막의 전기적 특성이 순수한 BFO 박막에 비해서 크게 향상되었다. BNFVO 박막에 최대 전압 910 kV/cm를 인가하였을 때, 1 kHz에서 측정된 잔류 분극(2Pr)과 항전기장(2Ec)은 37 μC/cm2, 748 kV/cm 이었고, BTFVO 박막에 최대 전압 950 kV/cm를 인가하였을 때, 잔류 분극(2Pr)과 항전기장(2Ec)은  65μC/cm2, 537 kV/cm 였다. 또한 순수한 BFO 박막과 BNFVO, BTFVO 박막의 누설 전류밀도는 인가된 전기장이 100 kV/cm 일 때 1.58 x 10–3 A/cm2, 2.75 x 10–7 A/cm2, 그리고 2.03 x 10–5 A/cm2을 각각 보였다. BNFVO 박막의 경우 순수한 BFO 박막보다 4승 작은 양호한 특성을 보였다. Nd, Tb 그리고 V이 동시 도핑된 BNFVO 박막과 BTFVO 박막의 구조 변화에 의해서 그레인 크기와 균일성이 순수한 BFO 빅막에 비해서 개선되었다

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