Mr. S. Sonai

Mr. S. Sonai, Assistant Professor
Research Centre and PG Department of Physics
The Madura College (Autonomous), Madurai – 625 011
Mobile: +91 96773 92350,

Ph.D. topic:

Synthesis, characterization and dielectric propertied of solid solutions of NaKNbO3 and BaTiO3 based lead free piezoelectric ceramics

Date of Registration : 23/02/2018
Registration no. : P5213
Date of viva voce examination :

About the topic:
This research work is (at starting stage) concerned with the synthesis and characterization of sodium potassium niobate (NaKNbO3) and barium titanate based lead free piezoelectric ceramics. The NaKNbO3 based BaTiO3 samples will be synthesized using solid-state reaction method. The structural, electrical, piezoelectric and other physical properties of the synthesized samples will be analyzed using techniques like powder X-ray diffraction, SEM, EDS, Ultra violet visible Spectroscopy, etc.

The use of lead-based materials represented as Pb(Zr1-xTix)O3 (PZT), has caused serious environmental problems owing to the high toxicity of lead oxide. Recent investigations of lead-free piezoelectric materials have been carried out to replace lead-containing materials. Among the various lead-free piezoelectric materials, Sodium potassium niobate Na0.5K0.5NbO3 (abbreviated as NKN) is considered as a promising candidate because hot-pressed NKN ceramics have a high Curie temperature, a high remnant polarization, a large piezoelectric longitudinal response and a high planar coupling coefficient. NKN-based ceramics have received considerable attention mainly due to its piezoelectric properties exist over a wide range of temperature and it has several possibilities for substitution and additions.

Thus a complete analysis of the sodium potassium niobate (NaKNbO3) based lead free piezoelectric ceramics, with their corresponding structural, electrical, optical, dielectric, piezoelectric properties and others will be carried out and executed in this proposed research work.


1. (1-x)Na0.5K0.5NbO3-xBaTiO3; x=0,0.2,0.4,0.6,0.8,1.0
2. (1-x)Na0.5K0.5NbO3-xSrTiO3; x=0,0.02,0.04,0.06,0.08,0.10
3. (1-x)Na0.5K0.5NbO3-x(Ba0.95Sr0.05TiO3); x=0,0.02,0.04,0.06,0.08,0.10
4. (1-x)Na0.5K0.5NbO3-xBa(Zr0.52Ti0.48)O3; x=0,0.02,0.03,0.04,0.05,0.07

List of publications:

Electronic structure and chemical bonding in La1-xSrxMnO3 perovskite ceramics, 
N. Thenmozhi, S. Sasikumar, S. Sonai and R. Saravanan, 
Materials Research Express, IOP Science,4,  046103 1-11 (2017),  
(Impact Factor: 1.449)
Investigation on interatomic chemical bonding and charge-related optical,
 multiferroic properties of La1−xZnxFeO3 bulk ceramics.                                                                                              
G.Gowri, R.Saravanan, N.Srinivasan, O.V.Saravanan, S.Sonai 
Materials Chemistry and Physics (Elsevier), 267, 124652 (2021)
(Impact Factor = 3.408)