TY  - JOUR
AU  - Schmidt, Dirk Oliver
AU  - Hoffmann-Eifert, Susanne
AU  - Zhang, Hehe
AU  - La Torre, Camilla
AU  - Besmehn, Astrid
AU  - Noyong, Michael
AU  - Waser, Rainer
AU  - Simon, Ulrich
TI  - Resistive Switching of Individual, Chemically Synthesized TiO $_{2}$ Nanoparticles
JO  - Small
VL  - 11
IS  - 48
SN  - 1613-6810
CY  - Weinheim
PB  - Wiley-VCH
M1  - FZJ-2015-06466
SP  - 6444–6456
PY  - 2015
AB  - Resistively switching devices are considered promising for next-generation nonvolatile random-access memories. Today, such memories are fabricated by means of “top–down approaches” applying thin films sandwiched between nanoscaled electrodes. In contrast, this work presents a “bottom–up approach” disclosing for the first time the resistive switching (RS) of individual TiO2 nanoparticles (NPs). The NPs, which have sizes of 80 and 350 nm, respectively, are obtained by wet chemical synthesis and thermally treated under oxidizing or vacuum conditions for crystallization, respectively. These NPs are deposited on a Pt/Ir bottom electrode and individual NPs are electrically characterized by means of a nanomanipulator system in situ, in a scanning electron microscope. While amorphous NPs and calcined NPs reveal no switching hysteresis, a very interesting behavior is found for the vacuum-annealed, crystalline TiO2–x NPs. These NPs reveal forming-free RS behavior, dominantly complementary switching (CS) and, to a small degree, bipolar switching (BS) characteristics. In contrast, similarly vacuum-annealed TiO2 thin films grown by atomic layer deposition show standard BS behavior under the same conditions. The interesting CS behavior of the TiO2–x NPs is attributed to the formation of a core–shell-like structure by re-oxidation of the reduced NPs as a unique feature.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000367917500010
DO  - DOI:10.1002/smll.201502100
UR  - https://juser.fz-juelich.de/record/256592
ER  -