Leakage Current Characteristics of Lead-Free K 0.5 Na 0.5 NbO 3 Ferroelectric Thin Films with (K,Na) Excess and Li Substitution

• Published in: Japanese Journal of Applied Physics Vol. 49; no. 9R; p. 95805
• Main Authors: Kim, Jin Soo, Lee, Sun Young, Ahn, Chang Won, Hwang, Hak In, Lee, Hai Joon, Bae, Se Hwan, Kim, Ill Won
• Format: Journal Article
• Language: English
• Published: 01-09-2010
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.49.095805

K
0.5
Na
0.5
NbO
3
thin films with (K,Na) excess and LiNbO
3
substitution were fabricated on a Pt substrate by a chemical solution deposition method. The K
0.5
Na
0.5
NbO
3
thin films with (K,Na) 10 mol % excess and LiNbO
3
5 mol % substitution showed a saturated ferroelectric polarization–electric field (
P
–
E
) hysteresis loop and the estimated remanent polarization (
P
r
) and coercive field (
E
c
) were 8.6 µC/cm
2
and 40 kV/cm at 280 kV/cm, respectively. Compared to pure K
0.5
Na
0.5
NbO
3
thin films, the ferroelectric polarization of the thin film was improved and leakage current densities were decreased. Moreover, the ferroelectric polarization and leakage current characteristics are stable for higher applied electric fields and elevated temperatures. The conduction behaviours of these films were analyzed by Schottky and Poole–Frenkel emission.