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Tuning Oxide Properties by Oxygen Vacancy Control During Growth and Annealing
Published on: June 9, 2023
Unlocking High Dielectric Tunability and Exceptional Electrocaloric Performance via Growth-Driven Domain Dynamics
Garima Kaura1, Naveen Goyal1, Fang Liu2,3
1Materials Research Centre, Indian Institute of Science, Bangalore, India.
Advanced Materials (Deerfield Beach, Fla.)
|June 23, 2026
Summary
This study optimizes lead-free ferroelectric films by controlling growth temperature, achieving a balance between dielectric tunability and electrocaloric performance for advanced electronics and refrigeration.
Area of Science:
- Materials Science
- Solid State Physics
- Thin Film Technology
Background:
- Lead-free ferroelectric films face challenges in simultaneously achieving high dielectric tunability, thermal/frequency stability, and efficient electrocaloric performance.
- These limitations hinder the deployment of eco-friendly tunable components and solid-state refrigeration.
Purpose of the Study:
- To establish quantitative growth-structure-property correlations in Ba0.7Ca0.3TiO3 thin films.
- To co-optimize dielectric and electrocaloric functionalities by controlling growth temperature.
Main Methods:
- Investigated Ba0.7Ca0.3TiO3 thin films grown at 630, 670, and 700°C.
- Utilized dielectric spectroscopy, Rayleigh analysis, phase-field simulations, and electrocaloric measurements.
- Analyzed intrinsic and extrinsic contributions to dielectric and electrocaloric behavior.
Main Results:
- Films grown at 630°C showed highest tunability (~90%) due to extrinsic mechanisms and mixed nano-domains.
- Films grown at 670°C offered stable tunability (~85%), low dielectric loss (<0.05), high CQF (~1.6e4), and excellent thermal/frequency stability.
- Films grown at 700°C exhibited superior electrocaloric coefficient (~0.025 K cm kV⁻¹), RC (~1900 J kg⁻¹), and RCP (~1755 K²).
Conclusions:
- Growth temperature is a critical parameter for tuning Ba0.7Ca0.3TiO3 thin films.
- Achieved trade-offs between tunability and stability, paving the way for adaptive microelectronics.
- Demonstrated high electrocaloric performance in lead-free films for solid-state refrigeration applications.
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