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Nanoscale Resistive Switching in Ultrathin PbZr 0.2 Ti 0.8 O 3 –La 0.7 Sr 0.3 MnO 3 Bilayer
Author(s) -
Band Tino,
Rata Diana A.,
Roth Robert,
Ebbinghaus Stefan G.,
Dörr Kathrin
Publication year - 2020
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201900609
Subject(s) - ferroelectricity , materials science , pulsed laser deposition , hysteresis , nanoscopic scale , perovskite (structure) , deposition (geology) , piezoresponse force microscopy , electric field , voltage , ionic bonding , nanotechnology , biasing , resistive touchscreen , condensed matter physics , analytical chemistry (journal) , thin film , optoelectronics , crystallography , ion , dielectric , chemistry , electrical engineering , physics , engineering , biology , paleontology , chromatography , quantum mechanics , organic chemistry , sediment
Electric switching of ultrathin ferroelectric films is vital for electronic elements such as multiferroic tunnel junctions, but the large required field may induce ionic motions as addressed here. Unipolar current–voltage ( I–V ) characteristics of ultrathin (3 nm) PbZr 0.2 Ti 0.8 O 3 (PZT) grown on La 0.7 Sr 0.3 MnO 3 (LSMO) by pulsed laser deposition have been investigated in an ambient‐condition force microscope. Topographic changes have been recorded after the I–V measurements. No ferroelectric switching is found, but resistive switching with features in agreement with earlier work on similar perovskite titanates. The onset of hysteretical I–V loops is correlated with a clear height increase in the contacted area under the Pt‐covered tip. The onset voltage of 4.5 V (−2.5 V) for positive (negative) tip bias is clearly different for the two voltage polarities. The observed height changes after applying electrical voltage reveal a volume expansion that must be attributed to chemical changes in both the PZT and the LSMO layers. A fast and a slow process of ionic motion or electrochemical reaction contributing to the observed features is identified. The slow one occurs at negative voltage, causes very large height increase, and is hypothetically attributed to processes following the electro‐splitting of the adsorbed surface water.