TY  - JOUR
A1  - Qiu, Xunlin
A1  - Mellinger, Axel
A1  - Wegener, Michael
A1  - Wirges, Werner
A1  - Gerhard, Reimund
T1  - Barrier discharges in cellular polypropylene ferroelectrets : how do they influence the electromechanical properties?
Y1  - 2007
ER  - 
TY  - JOUR
A1  - Mellinger, Axel
A1  - Flores Suárez, Rosaura
A1  - Singh, Rajeev
A1  - Wegener, Michael
A1  - Wirges, Werner
A1  - Gerhard, Reimund
T1  - Zerstörungsfreie Tomographie von Raumladungs- und Polarisationsverteilungen mittles Wärmepulsen
N2  - Non-destructive, three-dimensional imaging of space-charge and polarization distributions in electret materials has been implemented by means of laser-induced thermal pulses. In pyroelectric films of poled poly(vinylidene fluoride), images of up to 45 x 45 pixels with a depth resolution of less than 0.5 mu m and a lateral resolution of 40 mu m were recorded, the latter being limited by fast thermal diffusion in the absorbing metallic front electrode. Initial applications include the analysis of polarization distributions in corona-poled piezoelectric sensor cables and the detection of patterned space-charge distributions in polytetrafluoroethylene films.
Y1  - 2007
UR  - http://www.oldenbourg-link.com/loi/teme
U6  - https://doi.org/10.1524/teme.2007.74.9.437
SN  - 0171-8096
ER  - 
TY  - JOUR
A1  - Mellinger, Axel
A1  - Wegener, Michael
A1  - Wirges, Werner
A1  - Mallepally, Rajendar Reddy
A1  - Gerhard, Reimund
T1  - Thermal and temporal stability of ferroelectret films made from cellular polypropylene/air composites
Y1  - 2006
ER  - 
TY  - JOUR
A1  - Mellinger, Axel
A1  - Singh, Rajeev
A1  - Gerhard, Reimund
T1  - Fast thermal-pulse measurements of space-charge distributions in electret polymers
N2  - Space-charge depth profiles in various electret polymers have been measured in both the time and the frequency domain using thermal pulses and waves, respectively. A comparison of the two techniques on corona-charged polytetrafluoroethylene showed that the thermal-pulse method yielded similar results as the thermal-wave technique, but approximately 20-50 times faster. The article discusses sensitivity limitations as well as possible applications, including the real-time monitoring of space-charge decay under UV irradiation. (C) 2005 American Institute of Physics
Y1  - 2005
SN  - 0034-6748
ER  - 
TY  - JOUR
A1  - Mellinger, Axel
A1  - Singh, Rajeev
A1  - Wegener, Michael
A1  - Wirges, Werner
A1  - Gerhard, Reimund
A1  - Lang, Sidney B.
T1  - Three-dimensional mapping of polarization profiles with thermal pulses
N2  - High-resolution, large-area three-dimensional mapping of polarization profiles in electret polymers was carried out by means of a fast thermal pulse technique with a focused laser beam. A lateral resolution of 38 mu m and a near- surface depth resolution of less than 0.5 mu m was achieved. At larger depths, fast thermal diffusion in the metal electrode rather than the laser spot size becomes the limiting factor for the lateral resolution. (c) 2005 American Institute of Physics
Y1  - 2005
SN  - 0003-6951
ER  - 
TY  - JOUR
A1  - Mellinger, Axel
A1  - Camacho González, Francisco
A1  - Gerhard, Reimund
T1  - Photostimulated discharge in electret polymers : an alternative approach for investigating deep traps
N2  - The stability of space charge in electrets such as polytetrafluoroethylene (PTFE), polyethylene terephthalate (PETP) and polypropylene (PP) under ultraviolet irradiation has been investigated using photostimulated discharge spectroscopy. While only weak discharge currents were observed in PTFE coated with semitransparent gold electrodes, up to 15 pA/cm(2) were found in PETP around the UV absorption edge near 310 nm. Space charge profiles obtained with the piezoelectrically generated pressure step method indicate that near-surface charges were almost completely removed. In PP foam, recent findings of a UV-reduced d(33) coefficient were confirmed for exposure times of up to 3.5 h, and a discharge peak at 200 urn could be assigned to the charges stored on the surfaces of the voids. The unique morphology and the (quasi-) piezoelectric properties of cellular PP make it a role model for the future investigation of charge storage in electrets
Y1  - 2004
ER  - 
TY  - JOUR
A1  - Mellinger, Axel
A1  - Gonzalez, Francisco Camacho
A1  - Gerhard, Reimund
T1  - Ultraviolet-induced discharge currents and reduction of piezoelectric coefficient in cellular polypropylene films
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Gonzalez, Francisco Camacho
A1  - Mellinger, Axel
A1  - Gerhard, Reimund
A1  - Santos, Lucas F.
A1  - Faria, Roberto M.
T1  - Photo-stimulated discharge of highly insulating polymers (PTFE and PETP)
Y1  - 2002
SN  - 0-7803-7502-5
ER  - 
TY  - JOUR
A1  - Mellinger, Axel
A1  - Gonzalez, Francisco Camacho
A1  - Gerhard, Reimund
A1  - Santos, Lucas F.
A1  - Faria, Roberto M.
T1  - Phototstimulated discharge of corona and electron-beam charged electret polymers
Y1  - 2002
SN  - 0-7803-7560-2
ER  - 
TY  - JOUR
A1  - Mellinger, Axel
A1  - Wegener, Michael
A1  - Wirges, Werner
A1  - Gerhard, Reimund
T1  - Thermally stable dynamic piezoelectricity in sandwich films of porous and non-porous amorphous fluoropolymer
Y1  - 2001
ER  -