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Raman Analysis of Piezo-Ceramics
Non-destructive investigation of crystallographic orientation in piezoelectric
ceramics and their devices.
The examination of the relative intensity of selected
Raman modes allows measuring the average orientation
of domains in a micro-sized area. This allowed
to investigate the ferroelastic effect, and the link between
domain switching and crack growth resistance.
It has been determined that the anisotropic crack
growth of piezoceramics is to a large extent due to
the anisotropy of domain switching. Domains, in fact,
tend always to switch parallel to an applied tensile
stress direction. This plays a role in the enhanced
fracture toughness on preferential directions in piezoceramic
materials.
Marco Deluca
Institut für Struktur- und Funktionskeramik
an der MUL seit: 2009
Email: m.deluca@mcl.at
www.isfk.at
Zur Person:
MSc Chemical Engineering (Univ. Trieste – Italy)
PhD Materials Science (Kyoto Institute of Technology – Japan)
Piezo-ceramics such as PZT owe their outstanding
electromechanical coupling to the movement
of ferroelectric domains, i.e. subgrain uniformly
oriented regions. It is extremely important
for device design (and scientifically exciting) to
visualise domain structures on the microscale.
Raman spectroscopy is a powerful method that
enables to perform this task in a non-destructive
manner. A polarised laser beam interacts with
the vibrational energy of the investigated crystal,
giving information about lattice structure, orientation
and strain.
Raman analysis of domain orientation in the neighbourhood
of a Vickers indentation. Anisotropic domain switching
is present. The original poling direction is indicated
by the circled arrow.
Forschungspartner:
Forschungsschwerpunkte:
Raman spectroscopy of piezo-ceramics
Micro-analytical methods
Miniaturised mechanical testing of ceramics
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