The permittivity and refractive index measurements of doped barium titanate (BT-BCN)

Michael A. Meeker, Souvik Kundu, Deepam Maurya, Min Gyu Kang, Alejandro Sosa, Rathsara R.H.H. Mudiyanselage, Michael Clavel, Sreenivasulu Gollapudi, Mantu K. Hudait, Shashank Priya, Giti A. Khodaparast

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


While piezoelectric- ferroelectric materials offer great potential for nonvolatile random access memory, most commonly implemented ferroelectrics contain lead which imposes a challenge in meeting environmental regulations. One promising candidate for lead-free, ferroelectric material based memory is (1−x)BaTiO3−xBa(Cu1/3Nb2/3)O3 (BT-BCN), x=0.025. The samples studied here were grown on a Si substrate with an HfO2 buffer layer, thereby preventing the interdiffusion of BT-BTCN into Si. This study provides further insight into the physical behavior of BT-BCN that will strengthen the foundation for developing switching devices. The sample thicknesses ranged from 1.5 to 120 nm, and piezoelectric force microscopy was employed in order to understand the local ferroelectric behaviors. Dielectric constant as a function of frequency demonstrated enhanced frequency dispersion indicating the polar nature of the composition. The relative permittivity was found to change significantly with varying bias voltage and exhibited a tunability of 82%. The difference in the peak position during up and down sweeps is due to the presence of the spontaneous polarization. Furthermore, reflectometry was performed to determine the refractive index of samples with differing thicknesses. Our results demonstrate that refractive indices are similar to that of barium titanate. This is a promising result indicating that improved ferroelectric properties are obtained without compromising the optical properties.

Original languageEnglish (US)
Pages (from-to)793-798
Number of pages6
JournalOptical Materials
StatePublished - Nov 2017
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2017 Elsevier B.V.


  • Barium titanate
  • Ferroelectrics
  • Random access memory


Dive into the research topics of 'The permittivity and refractive index measurements of doped barium titanate (BT-BCN)'. Together they form a unique fingerprint.

Cite this