Lead zirconate, PbZrO3, has been of interest for dozens of years since its discovery [1-5]. Defects seem to play an important role regarding the microscopic origin of the formation of the so-called intermediate phase. Introduction of heterovalent cation Nb into crystal lattice of lead zirconate can create defects or may compensate charges produced by other defects. Additionally the low concentration of niobium leads to the existence of a new intermediate phase, properties of which depend on the dopant concentration [6]. Acoustic anomalies and precursor dynamics in high-quality niobium-doped lead zirconate single crystals investigated by Brillouin light scattering will be presented. Anomalous behaviour of the acoustic phonons was found to correlate with unexpected properties of the birefringence and piezoelectric effect in the temperature range in which permittivity does not obey the Curie-Weiss law. Moreover, temperature properties of acoustic phonons point to existence of the above-mentioned new intermediate phase. The Brillouin light scattering experiment was carried out on two PbZrO3:Nb single crystals grown by two different flux methods.
References
[1] G. Shirane, E. Sawaguchi, A. Takeda, Phys. Rev. 80, 485 (1950).
[2] V. J. Tennery, J. Electrochem. Soc. 112, 1117 (1965).
[3] L. Benguigui, J. Solid State Chem. 3, 381 (1971).
[4] Z. Ujma and J. Hańderek, Phys. Stat. Solidi (a) 28, 489 (1975).
[5] J.-H. Ko, M. Górny, A. Majchrowski, K. Roleder, A. Bussmann-Holder, Phys. Rev. B, 87, 184110 (2013).
[6] D. Kajewski, Z. Ujma, P. Zajdel, K. Roleder, Phys. Rev. B 93, 054104 (2016).