Nerija Zurauskiene | Center for Physical Sciences and Technology (original) (raw)
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Papers by Nerija Zurauskiene
—A new fast high-power fault current limiter made from epitaxial and polycrystalline La 0.83 Sr 0... more —A new fast high-power fault current limiter made from epitaxial and polycrystalline La 0.83 Sr 0.17 MnO 3 thin films and operating at 80 K has been demonstrated. An epitaxial film that exhibits a current-induced increase in its resistance is connected in series with a 50-Ω-impedance transmission line, while a polycrystalline film whose resistance decreases with an increase in current is connected in parallel. It has been demonstrated that, when the fault current pulse has an amplitude of 200 V, a rise time of 0.5 ns, and a pulselength of 18 ns, the limitation of its amplitude is 3.5 dB after the rise time and 8 dB at the end of the pulse.
— The effects of strong electric fields on the resis-tivity of thin nanostructured La-Ca(Sr)-Mn-O... more — The effects of strong electric fields on the resis-tivity of thin nanostructured La-Ca(Sr)-Mn-O films, deposited on lucalox substrates by the metal–organic chemical vapor deposition technique, are investigated using electrical pulses with a pulselength of 5 ns and an amplitude of up to 500 V. The influence of the chemical composition of these films is analyzed to determine the optimal conditions for their use as protectors against fast electromagnetic pulses (EMPs) when operating at the temperature of liquid nitrogen as well as at room temperatures. It is shown that by changing the doping material (using Ca instead of Sr), it is possible to reduce the threshold voltage in these films and to obtain better limiting characteristics at lower amplitudes of such pulsed electric fields. Index Terms— Electroresistance, intentional electromagnetic interference (IEMI), manganites, protectors against electromagnetic pulses (EMPs), strong electric field effects, thin films.
We have investigated the field ionization dynamics of shallow atoms in Ge:Sb,P, Si:P, and GaAs:C_... more We have investigated the field ionization dynamics of shallow atoms in Ge:Sb,P, Si:P, and GaAs:C_As systems at temperatures when in the tunneling process the acoustic lattice vibrations were important. A character of growth of the tunneling rate when lattice temperature was increased was found to depend on a structure of the investigated impurity energy spectrum in a semiconductor. In n-Ge:Sb,P, where energy separation between the ground and the first excited energy levels of Sb and P donors is small, Delta \varepsilon (Sb)=0.46 meV and Delta \varepsilon (P)=2.82 meV, the phonon activated tunneling through the excited Sb and P levels was observed in the temperature range from 4.2 to 6.5 K. In n-Si:P system, where the separation is large, Delta \varepsilon (P)=11.7 meV, a clear transition from acoustic phonon assisted electron tunneling from the ground phosphorus level to phonon activated tunneling was observed at 15 K. In p-GaAs:C_As only the phonon assisted tunneling of a hole from...
Thin Solid Films, 2006
ABSTRACT The electrical transport properties of thin films of perovskite manganites deposited on ... more ABSTRACT The electrical transport properties of thin films of perovskite manganites deposited on various substrates are summarised and discussed, focusing on the exploitation of their features for fast fault current limiter applications. The influence of strong electric fields on the resistivity of thin La0.67Ca0.33MnO3 and La0.83Sr0.17MnO3 films was investigated using nanosecond duration and subnanosecond rise time electrical pulses. It was obtained that a strong electric field induces a substantial resistance decrease in the films at a threshold electric field value. The ratio of the film resistance at low electric field and at strong electric field is the highest for polycrystalline films prepared on lucalox substrates. It was demonstrated that a limiter operating at room temperature and having 10 V threshold voltage, with 0.7 dB initial losses in the non-limiting regime and 6 dB attenuation in the limiting regime could be designed using 100–400 nm thickness polycrystalline manganite films. The limiter for low temperature operation having the same initial losses could be designed with the following parameters: 4 V threshold voltage and 8 dB attenuation in the limiting regime.
Lithuanian Journal of Physics, 2004
Physics Letters A, 1991
ABSTRACT Transient currents due to field ionization of shallow donors at the liquid helium temper... more ABSTRACT Transient currents due to field ionization of shallow donors at the liquid helium temperature are investigated in thin germanium samples by transient tunneling spectroscopy (TTS). The electron tunneling time from the antimony atoms to the conduction band has been measured as a function of electric field strength and compared with a simple scaled hydrogenic model.
Acta Physica Polonica A, 2002
Physical Review B, 2003
A thin InAs/GaAs wetting layer with shallowly formed InAs quantum dots ͑QD's͒ is investigated by ... more A thin InAs/GaAs wetting layer with shallowly formed InAs quantum dots ͑QD's͒ is investigated by means of optically detected microwave resonance spectroscopy. The absorption of W-band ͑95 GHz͒ microwaves is observed via the detection of changes in the total photoluminescence intensity of the InAs QD's. A strong and anisotropic signal at low fields is ascribed to cyclotron resonance of the electron in the two-dimensional wetting layer, corresponding to an effective mass of 0.053m 0 . Further microwave-induced signals at higher fields are tentatively attributed to magnetic resonance transitions between spin states of the holes confined in the shallow dots.
IEEE Transactions on Plasma Science, 2015
Materials Science Forum
Picosecond time-resolved streak-scope measurements of the electroluminescence (EL) of AlAs/GaAs d... more Picosecond time-resolved streak-scope measurements of the electroluminescence (EL) of AlAs/GaAs double-barrier resonant tunneling light-emitting diodes are presented The samples are excited by fast electrical pulses (250 ps rise and fall times) and both quantum well and bull; GaAs emissions are monitored, at room and liquid nitrogen temperatures. The effects of barrier thickness, temperature, voltage and device size and geometry on the switching speed are investigated. The optical response of the diodes is very fast (down to 200 ps), showing no significant dependence on temperature and barrier thickness.
The dependences of the fraction of electroporated mouse hepatoma MH-22A cells on the pulse intens... more The dependences of the fraction of electroporated mouse hepatoma MH-22A cells on the pulse intensity were obtained for the cells exposed to a single square-wave electric pulse with the duration from 95 ns to 20 μs. The amplitude of an electric pulse was varied from 0.4 to 12 kV/cm. Increasing the intensity of the electric field pulse increased the fraction of electroporated cells. The electric field, which lead to a given percentage of electroporation, decreased with increasing the pulse length. The dependence of the amplitude of the electric pulse required to electroporate 50 % of mouse hepatoma MH-22A cells on the pulse duration was also determined.
Thin Solid Films
The kinetics of resistivity and magnetoresistance change was studied during ageing of thin nanost... more The kinetics of resistivity and magnetoresistance change was studied during ageing of thin nanostructured La0.83Sr0.17MnO3 manganite films grown on lucalox (99.9% Al2O3 + 0.01% MgO) substrate by PI MOCVD method. It was obtained that accelerated ageing of the films in Ar atmosphere at temperatures 100-200 °C as well as long-term ageing during two years at room temperature leads to the significant increase of film resistivity, but has negligible influence on the magnetoresistance of the film in magnetic fields higher than 1 T. It was found that the accelerated ageing decreases demagnetization field of thin films and, as a result, the magnetoresistance anisotropy is decreased at low field region. The obtained results are analyzed using typical for topologically-disordered systems model of hierarchically limited relaxation dynamics described by stretched exponent. The analysis of resistivity vs. temperature dependence in paramagnetic state by using Mott’s variable range hopping model sh...
Materials Science Forum, 1999
ABSTRACT Experimental results on dynamical breakdown of metastable centers in Al0.3Ga0.7As caused... more ABSTRACT Experimental results on dynamical breakdown of metastable centers in Al0.3Ga0.7As caused by fast ramped electric fields are presented. The electrical breakdown was found to begin abruptly above threshold field F-th=(1.71+/-0.34)x10(5) V/cm. Persistent conductivity after the breakdown was observed at low temperatures. The breakdown is explained by ionization of DX centers by hot carriers.
Materials Science Forum, 1999
ABSTRACT Picosecond time-resolved streak-scope measurements of the electroluminescence (EL) of Al... more ABSTRACT Picosecond time-resolved streak-scope measurements of the electroluminescence (EL) of AlAs/GaAs double-barrier resonant tunneling light-emitting diodes are presented The samples are excited by fast electrical pulses (250 ps rise and fall times) and both quantum well and bull; GaAs emissions are monitored, at room and liquid nitrogen temperatures. The effects of barrier thickness, temperature, voltage and device size and geometry on the switching speed are investigated. The optical response of the diodes is very fast (down to 200 ps), showing no significant dependence on temperature and barrier thickness.
Applied Physics Letters, 2014
IEEE Transactions on Magnetics, 2014
The results of magnetoresistance (MR) and resistance relaxation of nanostructured La 1−x Ca x MnO... more The results of magnetoresistance (MR) and resistance relaxation of nanostructured La 1−x Ca x MnO 3 films, with different composition x grown by metal-organic chemical vapor deposition technique, are presented and compared with the La 0.83 Sr 0.17 MnO 3 films. The MR was investigated in pulsed magnetic fields up to 60 T in the temperature range 1.5-294 K while the relaxation processes were studied in pulsed fields up to 10 T and temperatures in the range of 80-300 K. It was demonstrated that at low temperatures the MR has higher values in the LCMO films in comparison with the LSMO ones, while at room temperatures, the highest MR values are obtained for the LSMO films. The fast (∼100 µs) and slow (∼ms) resistance relaxation processes were observed after the magnetic field pulse was switched off. It was shown that the fast process could be analyzed using the Kolmogorov-Avrami-Fatuzzo model, considering the reorientation of magnetic domains into their equilibrium state, while the slow process-by the Kohlrausch-Williams-Watts model considering the interaction of the magnetic moments in disordered grain boundaries having spin-glass properties. It was concluded that La 1−x Ca x MnO 3 films having a higher sensitivity and lower memory effects and should be favored for the development of fast pulsed magnetic field sensors operating at low temperatures.
Lithuanian Journal of Physics, 2014
ABSTRACT The results of colossal magnetoresistance (MR) relaxation investigations in nanostructur... more ABSTRACT The results of colossal magnetoresistance (MR) relaxation investigations in nanostructured and epitaxial La-Sr-Mn-O films grown by the MOCVD technique are presented. The films were studied in a pulsed magnetic field ranged from 2 to 10 T at the temperature of 80 K. The slow relaxation of resistance which takes place during milliseconds when the magnetic field is switched off is analysed using the Kohlrausch-Williams-Watts model. It was found that this relaxation is typical of spin-glass materials and is related with properties of disordered grain boundaries of nanostructured films. The MR relaxation of epitaxial films was not observed. The influence of film preparation conditions on MR relaxation was analysed in order to develop high pulsed magnetic field sensors exhibiting small dynamic "memory" effect and operating at low temperatures.
A 60 GHz microwave resonance investigation of shallowly formed InAs quantum dots embedded in GaAs... more A 60 GHz microwave resonance investigation of shallowly formed InAs quantum dots embedded in GaAs. [Proceedings of SPIE 6596, 659609 (2006)]. Nerija urauskienė, Griet Janssen, Etienne Goovaerts, Marek Godlewski, Vitalii Yu. Ivanov, Paul M. Koenraad. Abstract. ...
—A new fast high-power fault current limiter made from epitaxial and polycrystalline La 0.83 Sr 0... more —A new fast high-power fault current limiter made from epitaxial and polycrystalline La 0.83 Sr 0.17 MnO 3 thin films and operating at 80 K has been demonstrated. An epitaxial film that exhibits a current-induced increase in its resistance is connected in series with a 50-Ω-impedance transmission line, while a polycrystalline film whose resistance decreases with an increase in current is connected in parallel. It has been demonstrated that, when the fault current pulse has an amplitude of 200 V, a rise time of 0.5 ns, and a pulselength of 18 ns, the limitation of its amplitude is 3.5 dB after the rise time and 8 dB at the end of the pulse.
— The effects of strong electric fields on the resis-tivity of thin nanostructured La-Ca(Sr)-Mn-O... more — The effects of strong electric fields on the resis-tivity of thin nanostructured La-Ca(Sr)-Mn-O films, deposited on lucalox substrates by the metal–organic chemical vapor deposition technique, are investigated using electrical pulses with a pulselength of 5 ns and an amplitude of up to 500 V. The influence of the chemical composition of these films is analyzed to determine the optimal conditions for their use as protectors against fast electromagnetic pulses (EMPs) when operating at the temperature of liquid nitrogen as well as at room temperatures. It is shown that by changing the doping material (using Ca instead of Sr), it is possible to reduce the threshold voltage in these films and to obtain better limiting characteristics at lower amplitudes of such pulsed electric fields. Index Terms— Electroresistance, intentional electromagnetic interference (IEMI), manganites, protectors against electromagnetic pulses (EMPs), strong electric field effects, thin films.
We have investigated the field ionization dynamics of shallow atoms in Ge:Sb,P, Si:P, and GaAs:C_... more We have investigated the field ionization dynamics of shallow atoms in Ge:Sb,P, Si:P, and GaAs:C_As systems at temperatures when in the tunneling process the acoustic lattice vibrations were important. A character of growth of the tunneling rate when lattice temperature was increased was found to depend on a structure of the investigated impurity energy spectrum in a semiconductor. In n-Ge:Sb,P, where energy separation between the ground and the first excited energy levels of Sb and P donors is small, Delta \varepsilon (Sb)=0.46 meV and Delta \varepsilon (P)=2.82 meV, the phonon activated tunneling through the excited Sb and P levels was observed in the temperature range from 4.2 to 6.5 K. In n-Si:P system, where the separation is large, Delta \varepsilon (P)=11.7 meV, a clear transition from acoustic phonon assisted electron tunneling from the ground phosphorus level to phonon activated tunneling was observed at 15 K. In p-GaAs:C_As only the phonon assisted tunneling of a hole from...
Thin Solid Films, 2006
ABSTRACT The electrical transport properties of thin films of perovskite manganites deposited on ... more ABSTRACT The electrical transport properties of thin films of perovskite manganites deposited on various substrates are summarised and discussed, focusing on the exploitation of their features for fast fault current limiter applications. The influence of strong electric fields on the resistivity of thin La0.67Ca0.33MnO3 and La0.83Sr0.17MnO3 films was investigated using nanosecond duration and subnanosecond rise time electrical pulses. It was obtained that a strong electric field induces a substantial resistance decrease in the films at a threshold electric field value. The ratio of the film resistance at low electric field and at strong electric field is the highest for polycrystalline films prepared on lucalox substrates. It was demonstrated that a limiter operating at room temperature and having 10 V threshold voltage, with 0.7 dB initial losses in the non-limiting regime and 6 dB attenuation in the limiting regime could be designed using 100–400 nm thickness polycrystalline manganite films. The limiter for low temperature operation having the same initial losses could be designed with the following parameters: 4 V threshold voltage and 8 dB attenuation in the limiting regime.
Lithuanian Journal of Physics, 2004
Physics Letters A, 1991
ABSTRACT Transient currents due to field ionization of shallow donors at the liquid helium temper... more ABSTRACT Transient currents due to field ionization of shallow donors at the liquid helium temperature are investigated in thin germanium samples by transient tunneling spectroscopy (TTS). The electron tunneling time from the antimony atoms to the conduction band has been measured as a function of electric field strength and compared with a simple scaled hydrogenic model.
Acta Physica Polonica A, 2002
Physical Review B, 2003
A thin InAs/GaAs wetting layer with shallowly formed InAs quantum dots ͑QD's͒ is investigated by ... more A thin InAs/GaAs wetting layer with shallowly formed InAs quantum dots ͑QD's͒ is investigated by means of optically detected microwave resonance spectroscopy. The absorption of W-band ͑95 GHz͒ microwaves is observed via the detection of changes in the total photoluminescence intensity of the InAs QD's. A strong and anisotropic signal at low fields is ascribed to cyclotron resonance of the electron in the two-dimensional wetting layer, corresponding to an effective mass of 0.053m 0 . Further microwave-induced signals at higher fields are tentatively attributed to magnetic resonance transitions between spin states of the holes confined in the shallow dots.
IEEE Transactions on Plasma Science, 2015
Materials Science Forum
Picosecond time-resolved streak-scope measurements of the electroluminescence (EL) of AlAs/GaAs d... more Picosecond time-resolved streak-scope measurements of the electroluminescence (EL) of AlAs/GaAs double-barrier resonant tunneling light-emitting diodes are presented The samples are excited by fast electrical pulses (250 ps rise and fall times) and both quantum well and bull; GaAs emissions are monitored, at room and liquid nitrogen temperatures. The effects of barrier thickness, temperature, voltage and device size and geometry on the switching speed are investigated. The optical response of the diodes is very fast (down to 200 ps), showing no significant dependence on temperature and barrier thickness.
The dependences of the fraction of electroporated mouse hepatoma MH-22A cells on the pulse intens... more The dependences of the fraction of electroporated mouse hepatoma MH-22A cells on the pulse intensity were obtained for the cells exposed to a single square-wave electric pulse with the duration from 95 ns to 20 μs. The amplitude of an electric pulse was varied from 0.4 to 12 kV/cm. Increasing the intensity of the electric field pulse increased the fraction of electroporated cells. The electric field, which lead to a given percentage of electroporation, decreased with increasing the pulse length. The dependence of the amplitude of the electric pulse required to electroporate 50 % of mouse hepatoma MH-22A cells on the pulse duration was also determined.
Thin Solid Films
The kinetics of resistivity and magnetoresistance change was studied during ageing of thin nanost... more The kinetics of resistivity and magnetoresistance change was studied during ageing of thin nanostructured La0.83Sr0.17MnO3 manganite films grown on lucalox (99.9% Al2O3 + 0.01% MgO) substrate by PI MOCVD method. It was obtained that accelerated ageing of the films in Ar atmosphere at temperatures 100-200 °C as well as long-term ageing during two years at room temperature leads to the significant increase of film resistivity, but has negligible influence on the magnetoresistance of the film in magnetic fields higher than 1 T. It was found that the accelerated ageing decreases demagnetization field of thin films and, as a result, the magnetoresistance anisotropy is decreased at low field region. The obtained results are analyzed using typical for topologically-disordered systems model of hierarchically limited relaxation dynamics described by stretched exponent. The analysis of resistivity vs. temperature dependence in paramagnetic state by using Mott’s variable range hopping model sh...
Materials Science Forum, 1999
ABSTRACT Experimental results on dynamical breakdown of metastable centers in Al0.3Ga0.7As caused... more ABSTRACT Experimental results on dynamical breakdown of metastable centers in Al0.3Ga0.7As caused by fast ramped electric fields are presented. The electrical breakdown was found to begin abruptly above threshold field F-th=(1.71+/-0.34)x10(5) V/cm. Persistent conductivity after the breakdown was observed at low temperatures. The breakdown is explained by ionization of DX centers by hot carriers.
Materials Science Forum, 1999
ABSTRACT Picosecond time-resolved streak-scope measurements of the electroluminescence (EL) of Al... more ABSTRACT Picosecond time-resolved streak-scope measurements of the electroluminescence (EL) of AlAs/GaAs double-barrier resonant tunneling light-emitting diodes are presented The samples are excited by fast electrical pulses (250 ps rise and fall times) and both quantum well and bull; GaAs emissions are monitored, at room and liquid nitrogen temperatures. The effects of barrier thickness, temperature, voltage and device size and geometry on the switching speed are investigated. The optical response of the diodes is very fast (down to 200 ps), showing no significant dependence on temperature and barrier thickness.
Applied Physics Letters, 2014
IEEE Transactions on Magnetics, 2014
The results of magnetoresistance (MR) and resistance relaxation of nanostructured La 1−x Ca x MnO... more The results of magnetoresistance (MR) and resistance relaxation of nanostructured La 1−x Ca x MnO 3 films, with different composition x grown by metal-organic chemical vapor deposition technique, are presented and compared with the La 0.83 Sr 0.17 MnO 3 films. The MR was investigated in pulsed magnetic fields up to 60 T in the temperature range 1.5-294 K while the relaxation processes were studied in pulsed fields up to 10 T and temperatures in the range of 80-300 K. It was demonstrated that at low temperatures the MR has higher values in the LCMO films in comparison with the LSMO ones, while at room temperatures, the highest MR values are obtained for the LSMO films. The fast (∼100 µs) and slow (∼ms) resistance relaxation processes were observed after the magnetic field pulse was switched off. It was shown that the fast process could be analyzed using the Kolmogorov-Avrami-Fatuzzo model, considering the reorientation of magnetic domains into their equilibrium state, while the slow process-by the Kohlrausch-Williams-Watts model considering the interaction of the magnetic moments in disordered grain boundaries having spin-glass properties. It was concluded that La 1−x Ca x MnO 3 films having a higher sensitivity and lower memory effects and should be favored for the development of fast pulsed magnetic field sensors operating at low temperatures.
Lithuanian Journal of Physics, 2014
ABSTRACT The results of colossal magnetoresistance (MR) relaxation investigations in nanostructur... more ABSTRACT The results of colossal magnetoresistance (MR) relaxation investigations in nanostructured and epitaxial La-Sr-Mn-O films grown by the MOCVD technique are presented. The films were studied in a pulsed magnetic field ranged from 2 to 10 T at the temperature of 80 K. The slow relaxation of resistance which takes place during milliseconds when the magnetic field is switched off is analysed using the Kohlrausch-Williams-Watts model. It was found that this relaxation is typical of spin-glass materials and is related with properties of disordered grain boundaries of nanostructured films. The MR relaxation of epitaxial films was not observed. The influence of film preparation conditions on MR relaxation was analysed in order to develop high pulsed magnetic field sensors exhibiting small dynamic "memory" effect and operating at low temperatures.
A 60 GHz microwave resonance investigation of shallowly formed InAs quantum dots embedded in GaAs... more A 60 GHz microwave resonance investigation of shallowly formed InAs quantum dots embedded in GaAs. [Proceedings of SPIE 6596, 659609 (2006)]. Nerija urauskienė, Griet Janssen, Etienne Goovaerts, Marek Godlewski, Vitalii Yu. Ivanov, Paul M. Koenraad. Abstract. ...