PT Unknown
AU Kaps, S
TI Methodology of ZnO Based 1D Microstructures : from Synthesis to Application
PY 2015
PU Christian-Albrechts-Universität zu Kiel
WP https://macau.uni-kiel.de/receive/diss_mods_00016456
LA en
DE ZnO; magntoelectric; sensor; piezotronic; superhydrophobic
AB ZnO is among the most studied materials in the past decades. A large number
of synthesis routes and a unique combination of properties offer a wide range of
possible applications. This work focuses on the development of applications using
1D ZnO micro- and nanostructures.
The development starts with the introduction of a new synthesis process, flame
transport synthesis (FTS). The FTS allows the fabrication of various metal oxide
micro- and nanostructures. Depending on the used parameter set the structural
type can be modified leading to different morphologies, e.g., interconnected net-
works, core spike particles or large 1D single crystals. These resulting structures
were characterized by state of the art methods to determine their crystalline,
electric and piezoelectric properties. X-ray diffraction analysis revealed excellent
crystalline properties and the absence of pre-strain in 1D ZnO microrods. TEM
investigations showed the existence of twin boundaries in the spikes of core spike
particles. Electromechanical measurements were used to demonstrate the pre-
strain in ZnO microrods when attached to a plane substrate.
Electromechanical measurements inside SEM allowed the precise measurement
of the piezoresistive properties of individual ZnO microrods. The hydrophobic
and hydrophilic wetting states of ZnO are discussed and a theoretical model is
introduced which expands the common wetting theory and explains the wetting
of superhydrophobic surfaces. Magnetoelectric sensors based on ZnO microrods
are realized and investigated. The new concept of piezotronic measurements is
applied for the sensors and is compared to the classical piezoelectric measurement
concept. The comparison revealed a lower limit of detection for the piezotronic
sensor, which makes it a promising candidate for new applications.
PI Kiel
ER