Berlin 2015 – wissenschaftliches Programm

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KR: Fachgruppe Kristallographie

KR 6: Ceramics and Applications (DF jointly with KR)

KR 6.4: Hauptvortrag

Mittwoch, 18. März 2015, 12:30–13:00, EB 407

Investigation of dielectrics under electron irradiation — •Hans-Joachim Fitting — Institute of Physics, University of Rostock, D-18059 Rostock, Germany

Electron beam induced conductivity ( EBIC ) in insulating materials has been described by a flight-drift model of electrons and holes,[1] and then extended by an intrinsic field conductivity to a flight-drift-conduction model,[2], describing now the selfconsistent charge transport and storage in full insulating materials (c=0), as well as in semi-insulators and wide-gap semiconductors up to intrinsic conductivities of c = 10-6 S/m. This model reflects a more realistic simulation of electron spectroscopic processes in context with electrical charching and/or their prevention, [3]. Moreover, we found the mean relaxation time of ballistically excited electrons with 75 fs, [4]. The experimentally accessable quantities of field assisted total secondary electron emission σ(t) as well as the resulting surface potential V0(t) due to internal currents j(x,t), charges ρ(x,t), field F(x,t), and potential V(x,t) distributions are obtained. Thus a given Al2O3 ceramic sample series approaches an intrinsic electrical conductivity of c = (E-10 - E-8) S/m. [1] X. Meyza, D. Goeuriot, C. Guerret-Piécourt, D. Tréheux, and H.-J. Fitting, J. Appl. Phys. 94, 5384 (2003). [2] H.-J. Fitting, M. Touzin, J.A.P. 110, 044111 (2011) [3] M. Touzin, D. Goeuriot, C. Guerret-Piécourt, D. Juvé, D. Tréheux, and H.-J. Fitting, J.A.P, 99, 114110 (2006). [4] H.-J. Fitting and M. Touzin, J.A.P, 108, 033711 (2010)