Study of Tetragonal Phase in 0.4Na1/2Bi1/2TiO3-(0.6-x)SrTiO3-xPbTiO3 Solid Solutions by Second-Harmonic Generation

• Published in: Ferroelectrics Vol. 485; no. 1; pp. 53 - 57
• Main Authors: Birks, E., Kundzinsh, M., Nitiss, E., Ignatans, R., Dunce, M., Antonova, M., Sternberg, A.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 26-08-2015
• Subjects: NBT; Second harmonic generation; SHG; solid solution; structure
• ISSN: 0015-0193; 1563-5112
• DOI: 10.1080/00150193.2015.1060106

Description of the local symmetry of relaxor ferroelectrics, especially in connection with nature of polar nanoregions, is one of the key questions in research of relaxor ferroelectrics. Unlike such well-known relaxor ferroelectrics as PbMg
1/3
Nb
2/3
O
3
and (Pb,La)(Zr
0.65
Ti
0.35
)O
3
, ternary solid solutions 0.4Na
1/2
Bi
1/2
TiO
3
-(0.6-x)SrTiO
3
-xPbTiO
3
show clear coexistence of phases of tetragonal and cubic symmetry, which is established by x-ray diffractometry. Since the second-harmonic generation spectroscopy is a sensitive tool in determination of deviation from symmetry, containing a centre of inversion, it is used as an additional method in characterization of structure in 0.4Na
1/2
Bi
1/2
TiO
3
-(0.6-x)SrTiO
3
-xPbTiO
3
. Measurements indicate low, increasing intensity of the second-harmonic generation upon decreasing of temperature, for the samples with low concentration of PbTiO
3
. Whereas an abrupt change is observed at the phase transition between ferroelectric and relaxor states for the samples with higher concentrations of PbTiO
3
.