“Dielectric constants of bulk ferroelectric PZT measured by terahertz time-domain spectroscopy,” , M. Naftaly, M. G. Cain, S. Lepadatu, T. Buchacher & J. Allam, Advances in Applied Ceramics, Jan. 2016.
The complex permittivity of bulk ceramic ferroelectric of nominal composition PbZr0.4Ti0.6O3 was measured in the range 0.2–2 THz using transmission time-domain spectroscopy. The results indicate strong absorption and dispersion in this frequency range as often seen in highly disordered and polar materials. The results are compared to equivalent thin film data in the literature, and significant differences in the real and imaginary permittivity suggest that substrate clamping and degree of polarisation of the ferroelectric thin film materials affect dielectric properties even at these high frequencies.
“Simultaneous dynamic electrical and structural measurements of functional materials,” C. Vecchini, P. Thompson, M. Stewart, A. Muniz-Piniella, S. R. C. McMitchell, J. Wooldridge, S. Lepadatu, L. Bouchenoire, S. Brown, D. Wermeille, O. Bikondoa, C. A. Lucas, T. P. A. Hase, M. Lesourd, D. Dontsov, and M. G. Cain, Rev. Sci. Instrum., vol. 86, no. 10, pp. 103901–10, Oct. 2015.
A new materials characterization system developed at the XMaS beamline, located at the European Synchrotron Radiation Facility in France, is presented. We show that this new capability allows to measure the atomic structural evolution (crystallography) of piezoelectric materials whilst simultaneously measuring the overall strain characteristics and electrical response to dynamically (ac) applied external stimuli.