Enhanced polarization fatigue behavior in lead-free ferroelectric (K, Na)NbO3 thin films by Mn doping

• Published in: Journal of materials science. Materials in electronics Vol. 35; no. 23; p. 1564
• Main Authors: Phu, Nguyen Dang, Le, Xuan Luc, Duong, Nguyen Xuan
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-08-2024; Springer Nature B.V
• Subjects: Carrier density; Characterization and Evaluation of Materials; Chemistry and Materials Science; Current carriers; Defects; Domain walls; Doping; Ferroelectric materials; Ferroelectricity; Lead free; Leakage current; Materials fatigue; Materials Science; Memory devices; Nanotechnology devices; Niobates; Optical and Electronic Materials; Physical properties; Polarization; Sodium; Thin films
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-024-13340-7

Potassium sodium niobate (KNN) has attracted much interest as a promising lead-free ferroelectric candidate with its excellent physical properties for potential applications to novel nano-devices such as non-volatile ferroelectric memory. However, the use of KNN films in actual devices has been limited due to concerns in operational reliability (i.e., a polarization fatigue property). In this work, we demonstrate the enhancement of a polarization fatigue behavior in KNN thin films by doping of Mn ions. Ferroelectric fatigue is significantly suppressed in 0.4 mol% Mn-doped KNN films compared with pure KNN films. The amounts of mobile charged defects (e.g., oxygen vacancies and hole carriers produced with cation vacancies) are reduced in the presence of multivalent Mn dopants resulting in a decrease of leakage current density. The reduction of charged defect density can weaken the domain wall pinning effect enabling the polarization fatigue to be suppressed in KNN films. Our work is of practical interest for realizing lead-free ferroelectric memory devices with high performance.