Dresden 2009 – scientific programme

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DF: Fachverband Dielektrische Festkörper

DF 7: Advanced Dielectrics

DF 7.3: Talk

Tuesday, March 24, 2009, 15:00–15:20, WIL A317

Low voltage electron emission from [Pb(Mg_1/3Nb_2/3)O₃]_0.72 [PbTiO₃]_0.28 single crystals induced by ferroelectric polarization switching — •Oliver Mieth¹, Vinay S. Vidyarthi², Gerald Gerlach², Kathrin Dörr³, and Lukas M. Eng¹ — ¹Institute of Applied Physics, Technische Universität Dresden, Germany — ²Institute for Solid State Electronics, Technische Universität Dresden, Germany — ³Institute for Metallic Materials, IFW Dresden, D-01069 Dresden, Germany

Here we report on electron emission from [Pb(Mg_1/3Nb_2/3)O₃]_0.72 [PbTiO₃]_0.28 (PMN-PT) thin ferroelectric single crystals at ultra-low voltages down to 20 V per 400 µm thickness, and for up to 10⁹ switching cycles. PMN-PT samples were prepared with split gold top electrodes exhibiting a 25 µm wide gap region. Applying a sinusoidal voltage between the two top electrodes and the bottom electrode initiated electron emission from the gap region. The emitted electrons were collected under UHV conditions using two single electron counters arranged under an angle of 90^∘. Two emission regimes have been identified, which are clearly separated by the onset of complete ferroelectric polarization switching. This is also confirmed by recording nanoscale ferroelectric hysteresis loops by means of Piezoresponse Force Microscopy. The emitted electrons are found to have a broad energy distribution with the maximum kinetic energies reaching 110 eV and 50 eV for applied switching voltages of 140 V and 110 V, respectively. Our results confirm that polarization reversal is the governing mechanism behind the electron emission process.