Nanoscale Piezoelectric Properties and Phase Separation in Pure and La-Doped BiFeO3 Films Prepared by Sol-Gel Method | JoVE Visualize

Nanoscale Piezoelectric Properties and Phase Separation in Pure and La-Doped BiFeO₃ Films Prepared by Sol-Gel Method

Alina V Semchenko¹, Vitaly V Sidsky¹, Igor Bdikin²

¹Faculty of Physics and Information Technology, Francisk Skorina Gomel State University, 246019 Gomel, Belarus.

Materials (Basel, Switzerland)|April 3, 2021

View abstract on PubMed

Summary

Lanthanum doping and higher crystallization temperatures in bismuth ferrite (BiFeO3) thin films enhance grain size and self-polarization. However, this leads to a decrease in piezoelectric coefficients, impacting potential applications.

Area of Science:

Materials Science
Solid State Physics
Nanotechnology

Background:

Bismuth ferrite (BiFeO3) is a multiferroic material with potential applications in piezoelectric devices.
Understanding the influence of doping and processing parameters on BiFeO3 properties is crucial for optimizing its performance.

Purpose of the Study:

To investigate the effects of Lanthanum (La) doping and crystallization temperature on the structural, morphological, and piezoelectric properties of BiFeO3 thin films.
To explore the relationship between microstructure and piezoelectric activity in La-doped BiFeO3.

Main Methods:

Modified sol-gel technique with separate hydrolysis for preparing pure BiFeO3 and Bi0.9La0.1FeO3 (BLFO) thin films.
Investigation of phase structure, film morphology, and nanoscale piezoelectric properties.
Analysis of the impact of final crystallization temperature and La doping.

Main Results:

La doping and higher crystallization temperatures increased grain size and promoted a preferred (102) texture.
A significant decrease (approx. 2 times) in the average effective piezoelectric coefficient was observed in La-doped films.
An increase in the surface non-polar phase area (up to 60%) was attributed to phase separation.

Conclusions:

Piezoelectric activity in BiFeO3 thin films is directly correlated with their microstructure.
La doping enhances grain size and self-polarization but reduces piezoelectric coefficients, necessitating careful control of annealing conditions for piezoelectric applications.