The structural and electrical properties of BiFeO3 – Bi0.5K0.5TiO3 – BaTiO3 based solid solutions at the morphotropic phase boundary

Nagamalleswari Katragadda; Soham Kumar; P. Tulasirao; Weiguo Zhang; P. Shiv Halasyamani; Jyotika Nanda; Gopal K. Pradhan; Alicia María Manjón-Sanz; Pranab Mandal

doi:10.1016/j.mtcomm.2025.113030

The structural and electrical properties of BiFeO₃ – Bi_0.5K_0.5TiO₃ – BaTiO₃ based solid solutions at the morphotropic phase boundary

Nagamalleswari Katragadda
, Soham Kumar
, P. Tulasirao
, Weiguo Zhang
, P. Shiv Halasyamani
, Jyotika Nanda
, Gopal K. Pradhan
, Alicia María Manjón-Sanz
, Pranab Mandal

Powder Diffraction

Research output: Contribution to journal › Article › peer-review

1 Scopus citations

Abstract

Piezoelectric ceramics such as PbZr_1-xTi_xO₃ (PZT) show enhanced electro-mechanical properties at morphotropic phase boundary (MPB) separating two ferroelectric polar phases in the compositional phase diagram. Designing MPB in Pb-free perovskite oxide is challenging due to the lack of suitable polar tetragonal oxide with high Curie temperature. In this study, we explored the BiFeO₃ – Bi_0.5K_0.5TiO₃ – BaTiO₃ ternary phase diagram and searched for Bi-rich perovskite oxides as candidates for piezoceramics near MPB. The phase diagram offers a Bi-rich polar tetragonal (T_[001]) phase [0.75BaTiO₃–0.25(K_0.5Bi_0.5)TiO₃] and a well-known rhombohedral (R_[111]) phase BiFeO₃. A solid solution is observed in the entire range between the T_[001] phase and the R_[111] phase. Structural investigation through powder diffraction and Raman spectroscopy studies suggests the existence of a complex region (MPB), well separated by the rhombohedral and tetragonal phases. The composition (Bi_0.670K_0.050Ba_0.280)(Fe_0.62Ti_0.38)O₃ at the MPB shows a large signal piezoelectric coefficient of d₃₃^* = 41.5 pm/V at room temperature.

Original language	English
Article number	113030
Journal	Materials Today Communications
Volume	47
DOIs	https://doi.org/10.1016/j.mtcomm.2025.113030
State	Published - Jul 2025

Funding

NK, SK, PT, and PM acknowledge the financial support of the Early Career Research Grant from the Science and Engineering Research Board (SERB) (Grant No. ECR/2018/001252 ), and SRM University-AP (Grant No. SRMAP/URG/GENERAL/2024-25/015 ). A portion of this research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory (IPTS-29878). WZ and PSH thank the Welch Foundation (Grant E-1457 ) support. GKP and JN acknowledge the use of the Micro-Raman facility at the central research facility (CRF) of KIIT Deemed to be University, Bhubaneswar, and also thank the Science and Engineering Board for financial support ( CRG/2020/006190 ).

Keywords

Morphotropic phase boundary
Piezoceramics
Piezoelectric coefficient
Raman spectroscopy

Access to Document

10.1016/j.mtcomm.2025.113030

Cite this

Katragadda, N., Kumar, S., Tulasirao, P., Zhang, W., Halasyamani, P. S., Nanda, J., Pradhan, G. K., Manjón-Sanz, A. M., & Mandal, P. (2025). The structural and electrical properties of BiFeO₃ – Bi_0.5K_0.5TiO₃ – BaTiO₃ based solid solutions at the morphotropic phase boundary. Materials Today Communications, 47, Article 113030. https://doi.org/10.1016/j.mtcomm.2025.113030

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title = "The structural and electrical properties of BiFeO3 – Bi0.5K0.5TiO3 – BaTiO3 based solid solutions at the morphotropic phase boundary",

abstract = "Piezoelectric ceramics such as PbZr1-xTixO3 (PZT) show enhanced electro-mechanical properties at morphotropic phase boundary (MPB) separating two ferroelectric polar phases in the compositional phase diagram. Designing MPB in Pb-free perovskite oxide is challenging due to the lack of suitable polar tetragonal oxide with high Curie temperature. In this study, we explored the BiFeO3 – Bi0.5K0.5TiO3 – BaTiO3 ternary phase diagram and searched for Bi-rich perovskite oxides as candidates for piezoceramics near MPB. The phase diagram offers a Bi-rich polar tetragonal (T[001]) phase [0.75BaTiO3–0.25(K0.5Bi0.5)TiO3] and a well-known rhombohedral (R[111]) phase BiFeO3. A solid solution is observed in the entire range between the T[001] phase and the R[111] phase. Structural investigation through powder diffraction and Raman spectroscopy studies suggests the existence of a complex region (MPB), well separated by the rhombohedral and tetragonal phases. The composition (Bi0.670K0.050Ba0.280)(Fe0.62Ti0.38)O3 at the MPB shows a large signal piezoelectric coefficient of d33* = 41.5 pm/V at room temperature.",

keywords = "Morphotropic phase boundary, Piezoceramics, Piezoelectric coefficient, Raman spectroscopy",

author = "Nagamalleswari Katragadda and Soham Kumar and P. Tulasirao and Weiguo Zhang and Halasyamani, \{P. Shiv\} and Jyotika Nanda and Pradhan, \{Gopal K.\} and Manj{\'o}n-Sanz, \{Alicia Mar{\'i}a\} and Pranab Mandal",

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AU - Kumar, Soham

AU - Tulasirao, P.

AU - Zhang, Weiguo

AU - Halasyamani, P. Shiv

AU - Nanda, Jyotika

AU - Pradhan, Gopal K.

AU - Manjón-Sanz, Alicia María

AU - Mandal, Pranab

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N2 - Piezoelectric ceramics such as PbZr1-xTixO3 (PZT) show enhanced electro-mechanical properties at morphotropic phase boundary (MPB) separating two ferroelectric polar phases in the compositional phase diagram. Designing MPB in Pb-free perovskite oxide is challenging due to the lack of suitable polar tetragonal oxide with high Curie temperature. In this study, we explored the BiFeO3 – Bi0.5K0.5TiO3 – BaTiO3 ternary phase diagram and searched for Bi-rich perovskite oxides as candidates for piezoceramics near MPB. The phase diagram offers a Bi-rich polar tetragonal (T[001]) phase [0.75BaTiO3–0.25(K0.5Bi0.5)TiO3] and a well-known rhombohedral (R[111]) phase BiFeO3. A solid solution is observed in the entire range between the T[001] phase and the R[111] phase. Structural investigation through powder diffraction and Raman spectroscopy studies suggests the existence of a complex region (MPB), well separated by the rhombohedral and tetragonal phases. The composition (Bi0.670K0.050Ba0.280)(Fe0.62Ti0.38)O3 at the MPB shows a large signal piezoelectric coefficient of d33* = 41.5 pm/V at room temperature.

AB - Piezoelectric ceramics such as PbZr1-xTixO3 (PZT) show enhanced electro-mechanical properties at morphotropic phase boundary (MPB) separating two ferroelectric polar phases in the compositional phase diagram. Designing MPB in Pb-free perovskite oxide is challenging due to the lack of suitable polar tetragonal oxide with high Curie temperature. In this study, we explored the BiFeO3 – Bi0.5K0.5TiO3 – BaTiO3 ternary phase diagram and searched for Bi-rich perovskite oxides as candidates for piezoceramics near MPB. The phase diagram offers a Bi-rich polar tetragonal (T[001]) phase [0.75BaTiO3–0.25(K0.5Bi0.5)TiO3] and a well-known rhombohedral (R[111]) phase BiFeO3. A solid solution is observed in the entire range between the T[001] phase and the R[111] phase. Structural investigation through powder diffraction and Raman spectroscopy studies suggests the existence of a complex region (MPB), well separated by the rhombohedral and tetragonal phases. The composition (Bi0.670K0.050Ba0.280)(Fe0.62Ti0.38)O3 at the MPB shows a large signal piezoelectric coefficient of d33* = 41.5 pm/V at room temperature.

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