We have compared the acoustic paramagnetic resonance spectra found from unilluminated n-type chro... more We have compared the acoustic paramagnetic resonance spectra found from unilluminated n-type chromium-doped gallium arsenide with the predictions of a dynamic Jahn-Teller model for Cr2+.
The acoustoelectric effect resulting from the interaction between a longitudinal acoustic wave at... more The acoustoelectric effect resulting from the interaction between a longitudinal acoustic wave at 13 MHz and the two-dimensional electron gas (2-DEG) in a GaAs/AlGaAs heterostructure is described. Quantum oscillations in the acoustoelectric response as a function of applied magnetic field at a temperature of 4.2 K are observed. A simple model explaining how the acoustoelectric signal is produced, is discussed. In addition, the acoustoelectric signal obtained at temperatures of 4.2, 77, and 300 K for a wide range of gate voltages is described. Der akusto-elektrische Effekt, der aus der Wechselwirkung zwischen einer longitudinalen akustischen Welle bei 13 MHz und einem zweidimensionalen Elektrongas (2-DEG) in einer GaAs/AlGaAs Heterostruktur resultiert, wird beschrieben. Quanten-Oszillationen in akusto-elektrischen Respons als Funktion des benutzten magnetischen Feldes bei 4,2 K werden beobachtet. Ein einfaches Model, das die Entstehung des akusto-elektrischen Feldes erklart, wird diskutiert. Ein akusto-elektrisches Signal, das bei Temperaturen 4,2, 77 und 300 K in einem breiten Gatespannungsbereich gemessen wird, wird beschrieben.
Abstract The effect of spherical magnetic particles (Fe3O4) on liquid crystals (6CHBT) behavior a... more Abstract The effect of spherical magnetic particles (Fe3O4) on liquid crystals (6CHBT) behavior and structural changes in electric and weak magnetic fields was studied by means of the attenuation of surface acoustic wave (SAW) of frequency 30 MHz propagating along ferronematic liquid crystals. Three low volume concentrations ( Φ = 1 × 10 − 5 , 1 × 10 − 4 and 1 × 10 − 3 ) of spherical magnetic particles were added to liquid crystal during its isotropic phase. In contrast to undoped 6CHTB the distinctive SAW attenuation responses induced by both electric and magnetic fields in studied ferronematic liquid crystals below Freedericksz transition have been observed suggesting both structural changes and the orientational coupling between magnetic moments of magnetic particles and the director of the liquid crystal. The geometrical re-ranking of magnetic particles was registered only for some orientations of magnetic field. Observed results confirmed the significant influence of the presence of magnetic particles on the structural properties and following behavior of 6CHTB.
A considerable interest is given in experimental study of glassy materials with the fast ion tran... more A considerable interest is given in experimental study of glassy materials with the fast ion transport because they play an important role in a number of modern electrochemical devices. The relaxation and transport mechanisms in ion conductive glasses can be investigated by both acoustical spectroscopy and electrical investigation represented by conductivity spectroscopy. In the contribution we present some acoustical and electrical measurements utilized in the study of transport mechanisms and relaxation processes occurring in these glasses and some physical parameters are determined. Coherence between the acoustical and electrical properties is discussed, too.
ABSTRACT A new method of determining and characterization of traps at the insulator-semiconductor... more ABSTRACT A new method of determining and characterization of traps at the insulator-semiconductor interface is presented. This method, acoustic deep-level transient spectroscopy (A-DLTS), is based on the acoustoelectric response effect observed at the interface. A theoretical analysis of the acoustoelectric transient measurements in accordance to capacitance ones is also presented. The temperature dependence of the acoustoelectric response after bias voltage step application is investigated and the activation energies are calculated. Some other parameters of interface traps are also determined. The method is verified by the investigation of both, n- and p-type SiO2Si interface states.Eine neue Methode zur Charakterisierung der Traps in der Grenzschicht von MIS-Strukturen wird vorgestellt. Diese Methode, akustische-DLTS genannt (A-DLTS), besteht in der Beobachtung der akustoelektrischen Response an der Grenzschicht. Eine theoretische Analyse der akustoelektrischen Transientenmessungen erfolgt in Beziehung zu hnlichen kapazitiven Messungen. Die Abhngigkeit der akustoelektrischen Response wird nach sprunghafter nderung der Vorspannung untersucht, und die Aktivierungsenergien werden berechnet. Einige andere Parameter der Traps in der Grenzschicht werden ebenfalls bestimmt. Die Methode wird durch die Untersuchungen an n- und p-leitenden SiO2Si-Grenzschichten überprüft.
We have compared the acoustic paramagnetic resonance spectra found from unilluminated n-type chro... more We have compared the acoustic paramagnetic resonance spectra found from unilluminated n-type chromium-doped gallium arsenide with the predictions of a dynamic Jahn-Teller model for Cr2+.
The acoustoelectric effect resulting from the interaction between a longitudinal acoustic wave at... more The acoustoelectric effect resulting from the interaction between a longitudinal acoustic wave at 13 MHz and the two-dimensional electron gas (2-DEG) in a GaAs/AlGaAs heterostructure is described. Quantum oscillations in the acoustoelectric response as a function of applied magnetic field at a temperature of 4.2 K are observed. A simple model explaining how the acoustoelectric signal is produced, is discussed. In addition, the acoustoelectric signal obtained at temperatures of 4.2, 77, and 300 K for a wide range of gate voltages is described. Der akusto-elektrische Effekt, der aus der Wechselwirkung zwischen einer longitudinalen akustischen Welle bei 13 MHz und einem zweidimensionalen Elektrongas (2-DEG) in einer GaAs/AlGaAs Heterostruktur resultiert, wird beschrieben. Quanten-Oszillationen in akusto-elektrischen Respons als Funktion des benutzten magnetischen Feldes bei 4,2 K werden beobachtet. Ein einfaches Model, das die Entstehung des akusto-elektrischen Feldes erklart, wird diskutiert. Ein akusto-elektrisches Signal, das bei Temperaturen 4,2, 77 und 300 K in einem breiten Gatespannungsbereich gemessen wird, wird beschrieben.
Abstract The effect of spherical magnetic particles (Fe3O4) on liquid crystals (6CHBT) behavior a... more Abstract The effect of spherical magnetic particles (Fe3O4) on liquid crystals (6CHBT) behavior and structural changes in electric and weak magnetic fields was studied by means of the attenuation of surface acoustic wave (SAW) of frequency 30 MHz propagating along ferronematic liquid crystals. Three low volume concentrations ( Φ = 1 × 10 − 5 , 1 × 10 − 4 and 1 × 10 − 3 ) of spherical magnetic particles were added to liquid crystal during its isotropic phase. In contrast to undoped 6CHTB the distinctive SAW attenuation responses induced by both electric and magnetic fields in studied ferronematic liquid crystals below Freedericksz transition have been observed suggesting both structural changes and the orientational coupling between magnetic moments of magnetic particles and the director of the liquid crystal. The geometrical re-ranking of magnetic particles was registered only for some orientations of magnetic field. Observed results confirmed the significant influence of the presence of magnetic particles on the structural properties and following behavior of 6CHTB.
A considerable interest is given in experimental study of glassy materials with the fast ion tran... more A considerable interest is given in experimental study of glassy materials with the fast ion transport because they play an important role in a number of modern electrochemical devices. The relaxation and transport mechanisms in ion conductive glasses can be investigated by both acoustical spectroscopy and electrical investigation represented by conductivity spectroscopy. In the contribution we present some acoustical and electrical measurements utilized in the study of transport mechanisms and relaxation processes occurring in these glasses and some physical parameters are determined. Coherence between the acoustical and electrical properties is discussed, too.
ABSTRACT A new method of determining and characterization of traps at the insulator-semiconductor... more ABSTRACT A new method of determining and characterization of traps at the insulator-semiconductor interface is presented. This method, acoustic deep-level transient spectroscopy (A-DLTS), is based on the acoustoelectric response effect observed at the interface. A theoretical analysis of the acoustoelectric transient measurements in accordance to capacitance ones is also presented. The temperature dependence of the acoustoelectric response after bias voltage step application is investigated and the activation energies are calculated. Some other parameters of interface traps are also determined. The method is verified by the investigation of both, n- and p-type SiO2Si interface states.Eine neue Methode zur Charakterisierung der Traps in der Grenzschicht von MIS-Strukturen wird vorgestellt. Diese Methode, akustische-DLTS genannt (A-DLTS), besteht in der Beobachtung der akustoelektrischen Response an der Grenzschicht. Eine theoretische Analyse der akustoelektrischen Transientenmessungen erfolgt in Beziehung zu hnlichen kapazitiven Messungen. Die Abhngigkeit der akustoelektrischen Response wird nach sprunghafter nderung der Vorspannung untersucht, und die Aktivierungsenergien werden berechnet. Einige andere Parameter der Traps in der Grenzschicht werden ebenfalls bestimmt. Die Methode wird durch die Untersuchungen an n- und p-leitenden SiO2Si-Grenzschichten überprüft.
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Papers by Peter Bury