Regensburg 2016 – wissenschaftliches Programm

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KR: Fachgruppe Kristallographie

KR 1: Poster

KR 1.2: Poster

Mittwoch, 9. März 2016, 18:00–20:00, Poster E

Compositional influence on the pyroelectric coefficient of (1−x)PMN–xPT — •Sven Jachalke, Erik Mehner, Hartmut Stöcker, Erik Schleicher, Tilmann Leisegang, and Dirk C. Meyer — TU Bergakademie Freiberg, Institut für Experimentelle Physik, Leipziger Str. 23, 09596 Freiberg

Solid solutions of lead magnesium niobate – Pb(Mg_1/3Nb_2/3)O₃, PMN – and lead titanate – PbTiO₃, PT – in different compositions – (1−x)PMN–xPT – attract a large scientific interest due to their superb electromechanical and electrothermal properties, especially near the morphotropic phase boundary around x = 0.30. The present study focuses on the pyroelectric properties, i.e. the change of spontaneous polarization due to temperature fluctuations. Pyroelectric coefficients p(T) of single crystals are determined systematically with respect to different compositions (x = 0.25 to x = 0.32) and crystallographic orientations (<111>, <011> and <001>), including ferroelectric-to-ferroelectric and ferroelectric-to-dielectric phase transitions (at the Curie temperature T_C), in the temperature range of 273 K to 423 K. Data acquisition and analysis using the Sharp-Garn-method [1] allow separating the pyroelectric from disturbing non-pyroelectric current signals and yield temperature dependent pyroelectric coefficients (accuracy 1–5 %) and polarization.

[1] L. E. Garn and E. J. Sharp, “Use of low-frequency sinusoidal temperature waves to separate pyroelectric currents from nonpyroelectric currents”, J. Appl. Phys., Vol. 53, No. 12, p. 8974, 1982.