Influence of Excess Potassium on Structural and Ferroelectric Properties of Lead-Free Bi0.5K0.5TiO₃ Thin Films

Nguyen Ngoc Minh; Bui Van Dan; Nguyen Duc Minh; Guus Rijnders; Ngo Duc Quan

doi:10.1166/jnn.2021.19117

Influence of Excess Potassium on Structural and Ferroelectric Properties of Lead-Free Bi_0.5K_0.5TiO₃ Thin Films

J Nanosci Nanotechnol. 2021 Apr 1;21(4):2681-2686. doi: 10.1166/jnn.2021.19117.

Authors

Nguyen Ngoc Minh¹, Bui Van Dan¹, Nguyen Duc Minh², Guus Rijnders³, Ngo Duc Quan⁴

Affiliations

¹ Electrical and Electronic Faculty, Hung Yen University of Technology and Education, Hung Yen Province 160000, Vietnam.
² International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology, Hanoi 100000, Vietnam.
³ MESA+Institute for Nanotechnology, University of Twente, 7500, AE, Enschede, The Netherlands.
⁴ School of Engineering Physics, Hanoi University of Science and Technology, Hanoi 100000, Vietnam.

PMID: 33500093
DOI: 10.1166/jnn.2021.19117

Abstract

Lead-free Bi_0.5K_0.5TiO₃ (BKT) ferroelectric films were synthesized on Pt/Ti/SiO₂/Si substrates via the chemical solution deposition. The influence of the excess potassium on the microstructures and the ferroelectric properties of the films was investigated in detail. The results showed that the BKT films have reached the well-crystallized state in the single-phase perovskite structure with 20 mol.% excess amount of potassium. For this film, the ferroelectric properties of the films were significantly enhanced. The remnant polarization (P_r) and maximum polarization (P_m) reached the highest values of 9.4 μC/cm₂ and 32.2 μC/cm₂, respectively, under the electric field of 400 kV/cm.