J. Phys. IV France 08 (1998) Pr9-105-Pr9-108
Anomalous elastic and dielectric behavior in nanocrystalline Ca-modified lead titanate (PTC) filmsC. Ziebert1, J.K. Krüger1, R. Birringer1, H. Schmitt1 and B. Jiménez2
1 Univeristät des Saarlandes, Fachbereich Physik, Bau 38, 66123 Saarbrücken, Germany
2 Instituto de Ciencia de Materiales de Madrid, CSIC, Campus de Cantoblanco s/n, 28049 Madrid, Spain
Thin amorphous PTC-films of 1 µm thickness were produced by rf-sputtering at room temperature. A subsequent annealing process enabled us to prepare different grain sizes which have been characterised by x-ray powder diffraction. At the transition from the amorphous to the nanocrystalline state the elastic modulus c11 measured by HR-Brillouin spectroscopy exhibited a surprising instability. The dielectric constant showed not only the expected increase with increasing grain size but also a significant relaxor behavior.
© EDP Sciences 1998