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1

Applicable Damage of High-T_{ rm c} YbaCuO Superconducting Tapes by Current and Laser Pulses

100%

Kiprijanovič O., Ašmontas S., Anisimovas F., Gradauskas J.

Acta Physica Polonica A

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2011

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vol. 119

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issue 2

256-258

EN

Damage and irreversible damage of YBaCuO tapes with high density current after switching from superconducting to normal state are investigated. Quasi-homogeneous current distribution across the tape in superconducting state can cause perfect tape damage or irreversible damage when current is slightly above critical value. The model of the tape heating during the optically initiated switching from superconducting to normal state is proposed. Analysis of causes inducing damage shows necessity to consider 0.5T_{m} damage criterion because of strong current influence on the damage processes. Possible damage mechanisms are described and crack tips motion simultaneously with switching from superconducting to normal state is considered. Application of optically illuminated YBaCuO tapes with nanosecond duration current pulses on the base of the described mechanisms is proposed.

2

Response of Grained La_{0.67}Ca_{0.33}MnO_3 Films to Microwave Radiation and the Method for Measuring Electrical Resistance of Grains

76%

Repšas K., Laurinavičius A., Vaškevičius R., Anisimovas F., Deksnys A., Vengalis B.

Acta Physica Polonica A

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2006

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vol. 110

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issue 4

537-544

EN

It was found that the response of grained La_{0.67}Ca_{0.33}MnO_3 films to microwave radiation is of thermal nature. A nonresonant method for measuring of the electric resistance of grains was developed. It allows one to avoid the influence of the magnetic field of the wave on the measurement results. The measurements of the temperature dependences of the grain electric resistance indicate that in the vicinity of the maximum-resistance temperature T_m, the intrinsic electric resistance of the grains is more than by two orders of magnitude lower than the film resistance measured by applying the dc current. The obtained experimental results agree well with those given by resonant techniques.

3

Magnetoresistive Properties of Manganite-Based Heterojunctions

76%

Devenson J., Vengalis B., Lisauskas V., Oginskis A., Anisimovas F., Ašmontas S.

Acta Physica Polonica A

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2009

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vol. 115

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issue 6

1130-1132

EN

Hole-doped La_{2/3}Ba_{1/3}MnO_{3} (LBaMO), La_{2/3}Ca_{1/3}MnO_{3} (LCaMO) and La_{2/3}Ce_{1/3}MnO_{3} (LCeMO) thin films were grown heteroepitaxially on 0.1 wt.% Nb-doped SrTiO_{3}(100) (STON) substrates by magnetron sputtering. The prepared LBaMO/STON, LCaMO/STON, LCeMO/STON heterostructures demonstrated nonlinear rectifying current-voltage characteristics. Negative magnetorestance values have been indicated at low bias, meanwhile bias-dependent magnetoresistance has been measured at positive bias voltage values U > U_d where U_d is the interfacial potential, corresponding to a steep current increase at a forward bias.

4

Synthesis and Electrical Properties of La-Pr-Mn-O Thin Films and Heterostructures

76%

Butkutė R., Anisimovas F., Oginskis A., Steikūnienė A., Devenson J., Vengalis B.

Acta Physica Polonica A

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2007

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vol. 111

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issue 1

111-115

EN

In this paper we report the results of synthesis and study of both ceramic samples and thin films of electronically doped La_{0.7}Pr_{0.3}MnO_3 and related heterostructures composed of La_{0.7}Pr_{0.3}MnO_3 and p-type La_{0.67}Ca_{0.33}MnO_3. The ceramic La_{0.7}Pr_{0.3}MnO_3 samples were prepared by a conventional solid state reaction technique. Single phase La_{0.7}Pr_{0.3}MnO_3 thin films and La_{0.7}Pr_{0.3}MnO_3/La_{0.67} Ca_{0.33}MnO_3 heterostructures were grown on lattice-matched perovskite NdGaO_3 substrates by pulsed laser deposition. Electron doping was indicated both for ceramic La_{0.7}Pr_{0.3}MnO_3 samples and thin films from thermopower data. Both ceramic samples and thin films of La_{0.7}Pr_{0.3}MnO_3 demonstrated resistivity of about 10 mΩ cm at 300 K and semiconductor-like resistance vs. temperature behavior with cooling down to 78 K. Meanwhile, the resistance of the La_{0.7}Pr_{0.3}MnO_3/La_{0.67}Ca_{0.33}MnO_3 interface showed an anomalous peak at 185 K. A series of post-deposition annealing experiments demonstrated a crucial role of annealing temperature and ambience on both electrical and magnetic properties of La_{0.7}Pr_{0.3}MnO_3 material and the heterostructures.

5

Reversible Resistive Switching in Electrically Nonhomogeneous La_{0.67}Ca_{0.33}MnO_3 Thin Films by Short Electrical Pulses

76%

Lučun A., Kiprijanovič O., Ašmontas S., Anisimovas F., Maneikis A., Sužied.lis A., Vengalis B.

Acta Physica Polonica A

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2008

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vol. 113

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issue 3

1059-1062

EN

Resistance changes in thin electrically nonhomogeneous La_{0.67}Ca_{0.33}MnO_3 films were investigated using electrical pulses of nanosecond duration in the 80-300 K temperature range. Two types of reversible switching to higher resistive states with different starting temperature induced by series of the positive pulses were observed. Possible mechanisms of the resistance switching by short electrical pulses in the vicinity of T_m and at 80-90 K are discussed.

6

Growth and Investigation of p-La_{2/3}Ca_{1/3}MnO_3/n-Si Heterostructures

76%

Anisimovas F., Butkutė R., Devenson J., Maneikis A., Stankevič V., Pyragas V., Vengalis B.

Acta Physica Polonica A

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2008

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vol. 113

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issue 3

997-1000

EN

We report the fabrication and investigation of p-n diode structures based on thin hole-doped La_{2/3}Ca_{1/3}MnO_3 films grown on n-type silicon substrates. La_{2/3}Ca_{1/3}MnO_3 films with typical thickness of about 400 nm were prepared using pulsed laser deposition. Reflection high-energy electron diffraction measurements revealed polycrystalline quality of La_{2/3}Ca_{1/3}MnO_3 thin films on Si substrates. The surface roughness of La_{2/3}Ca_{1/3}MnO_3 films investigated by atomic force microscopy was found to be in the range of 25÷30 nm. Studies of electrical properties showed that La_{2/3}Ca_{1/3}MnO_3/Si heterostructures exhibit nonlinear asymmetric I-V characteristics both at room temperature and at 78 K. Furthemore, it was shown that these I-V dependences are sensitive to magnetic field, especially at lower voltages.

7

Electroresistance of La-Ca-MnO Thin Films

64%

Cimmperman P., Stankevič V., Žurauskienė N., Balevičius S., Anisimovas F., Paršeliūnas J., Kiprijanovič O., Altgilbers L.

Acta Physica Polonica A

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2004

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vol. 105

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issue 1-2

107-114

EN

Epitaxial, textured, and polycrystalline La_{0.7}Ca_{0.3}Mn O_3 films, having about 150 nm thickness, were prepared by pulsed laser deposition techniques onto (110) NdGaO_3, MgO and lucalox substrates and investigated using 10 ns duration, 0.5 ns rise time electrical pulses having amplitude up to 500 V. Electroresistance of the films [R(E)-R(0)]/R(0) was investigated up to 80 kV/cm electric field strengths in temperatures ranging from 300 K to 4.2 K. Strong (up to 93%) negative electroresistance was obtained in polycrystalline La_{0.7}Ca_{0.3}MnO_3 films prepared on MgO and lucalox substrates. The epitaxial films grown on NdGaO_3 substrate demonstrated only a small resistance change due to Joule heating induced by a current pulse. It was concluded that electroresistance manifests itself in strongly inhomogeneous manganites films exhibiting a large number of structural imperfections producing ferromagnetic tunnel junction nets.

8

Electroresistance of Electrically Nonhomogeneous La_{0.67}Ca_{0.33}MnO_3/MgO Thin Films

64%

Kiprijanovič O., Lučun A., Ašmontas S., Anisimovas F., Butkutė R., Maneikis A., Sužiedėlis A., Vengalis B.

Acta Physica Polonica A

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2007

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vol. 111

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issue 1

141-146

EN

Current and electrical field-induced electroresistive effects were investigated for La_{0.67}Ca_{0.33}MnO_3/MgO thin films demonstrating nanosized electrical inhomogeneities. Two different models based on enhanced conductivity of intergrain boundaries by injecting spin-polarized carriers from ferromagnetic grains and electrical field-enhanced hopping of carriers in high resistance intergrain media were carried out to explain nonlinear electrical properties of the films.

9

Magnetoresistance of Polycrystalline La_{0.7}Ca_{0.3}MnO_3 Films in a Microwave Magnetic Field

64%

Lučun A., Butkutė R., Maneikis A., Kiprijanovič O., Anisimovas F., Gradauskas J., Sužiedėlis A., Vengalis B., Kancleris Ž., Ašmontas S.

Acta Physica Polonica A

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2007

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vol. 111

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issue 1

147-152

EN

We present new experimental evidence indicating the importance of magnetic field component of microwave field (f=9.4 GHz) for magnetoresistive properties of polycrystalline La_{0.7}Ca_{0.3}MnO_3 films. The microwave measurements revealed a different character of the temperature-dependent electrical resistance of polycrystalline La_{0.7}Ca_{0.3}MnO_3 films placed in the centre (maximal amplitude of H_{10} wave vector) and at a narrow wall of the wave-guide (reduced H_{10} amplitude). Theoretical estimations of the influence of substrate onto distribution of microwave electric and magnetic fields in the waveguide were performed using the finite-difference time-domain method.

10

Investigation of Heterostructure Formed from Hole- and Electron-Doped Lanthanum Manganites

64%

Vengalis B., Rosa A., Devenson J., Šliužienė K., Lisauskas V., Oginskis A., Anisimovas F., Pyragas V.

Acta Physica Polonica A

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2005

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vol. 107

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issue 2

290-293

EN

High crystalline quality films of n-La_{2/3}Ce_{1/3}MnO_3, p-La_{2/3}Ca_{1/3}MnO_3 and related p-n diode structures were grown heteroepitaxially on lattice-matched SrTiO_3(100) substrates by dc magnetron sputtering and pulsed laser deposition. The La_{2/3}Ce_{1/3}Mn O_3/La_{2/3}Ca_{1/3}MnO_3 bilayer was patterned into a strip-like geometry to investigate electrical properties of the interface. Significant magnetoresistance values and nonlinear current-voltage characteristics were indicated for the interface of the p-n diode heterostructure.

11

Frequency Dependence of Electrical Response of Polycrystalline LCMO Thin Films

64%

Ašmontas S., Anisimovas F., Balevičius S., Cimmperman P., Gradauskas J., Lučun A., Stankevič V., Sužiedėlis A., Vengalis B., Žurauskienė N.

Acta Physica Polonica A

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2005

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vol. 107

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issue 1

193-197

EN

Influence of strong electric field in wide frequency range (from DC to 35 GHz) on electrical resistance of thin La_{0.67}Ca_{0.33}MnO_3 polycrystalline manganite films was investigated in the range of (78÷300) K. Different behavior of resistance change vs. temperature was observed when pulsed DC electric field and microwaves were applied to the films. When pulsed DC electric field is applied the electric-field-induced resistance change ("electroresistance") of manganite film depended nearly monotonically on temperature. However, in microwave electric fields a non-monotonic character of the electroresistance temperature dependence was observed. The dependence of the electroresistance on quality of manganite films was observed in case of microwaves. The experimental findings are explained assuming different electrical current mechanisms in case of DC and microwave fields. The applied voltage drops mainly across the grains of polycrystalline film due to a presence of displacement currents in case of microwaves, whereas in DC case the voltage drop is across the grain boundaries.

Refine search results

Applicable Damage of High-T_{ rm c} YbaCuO Superconducting Tapes by Current and Laser Pulses

Response of Grained La_{0.67}Ca_{0.33}MnO_3 Films to Microwave Radiation and the Method for Measuring Electrical Resistance of Grains

Magnetoresistive Properties of Manganite-Based Heterojunctions

Synthesis and Electrical Properties of La-Pr-Mn-O Thin Films and Heterostructures

Reversible Resistive Switching in Electrically Nonhomogeneous La_{0.67}Ca_{0.33}MnO_3 Thin Films by Short Electrical Pulses

Growth and Investigation of p-La_{2/3}Ca_{1/3}MnO_3/n-Si Heterostructures

Electroresistance of La-Ca-MnO Thin Films

Electroresistance of Electrically Nonhomogeneous La_{0.67}Ca_{0.33}MnO_3/MgO Thin Films

Magnetoresistance of Polycrystalline La_{0.7}Ca_{0.3}MnO_3 Films in a Microwave Magnetic Field

Investigation of Heterostructure Formed from Hole- and Electron-Doped Lanthanum Manganites

Frequency Dependence of Electrical Response of Polycrystalline LCMO Thin Films