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1

Magnetoresistive Properties of Manganite-Based Heterojunctions

100%

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.

2

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

100%

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.

3

Phase Separation and Microwave Response of Epitaxial and Polycrystalline Manganite Films

84%

Ašmontas S., Abrutis A., Gradauskas J., Lučun A., Oginskis A., Plaušinaitienė V., Sužiedėlis A., Vengalis B.

Acta Physica Polonica A

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2004

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vol. 105

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issue 1-2

141-147

EN

The resistance, magnetoresistance, and resistance response under microwave irradiation (f=10 and 35 GHz) were measured for epitaxial and polycrystalline La_{0.67}Ca_{0.33}MnO_3 and La_{0.67}Sr_{0.33}MnO_3 thin films in the temperature range 78÷300 K. The microwave induced resistance increase observed for the epitaxial films in a narrow temperature range below the ferromagnetic to paramagnetic transition temperature T_c certifies coexistence of low resistance (ferromagnetic) and high resistance (paramagnetic) regions in the manganites. Resistance of polycrystalline films decreased under microwave irradiation in a wide temperature range below T_c. The effect was explained in terms of microwave assisted hopping of carriers in high resistance regions formed at grain boundaries of the polycrystalline films.

4

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

84%

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.

5

Growth and Investigation of Heterostructures Based on Multiferroic BiFeO_3

84%

Vengalis B., Devenson J., Oginskis A., Butkutė R., Maneikis A., Steikūnienė A., Dapkus L., Banys J., Kinka M.

Acta Physica Polonica A

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2008

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vol. 113

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issue 3

1095-1098

EN

We report heteroepitaxial growth of multiferroic BiFeO_3 thin films by RF magnetron sputtering on lattice-matched SrTiO_3 substrates, as well as preparation and electrical properties of the heterostructures formed by growing BiFeO_3 thin films on highly conductive LaNiO_3 films and n-Si substrates. Nonlinear and rectifying current-voltage (I-U) characteristics were revealed for the heterojunctions in a wide temperature range (T=78-300 K).

6

Valence States of Metal Ions in La_{0.7}Ce_{0.3}MnO_3 Thin Films

68%

Mickevičius S., Bondarenka V., Grebinskij S., Oginskis A., Butkutė R., Tvardauskas H., Vengalis B., Orlowski B., Osinniy V., Pietrzyk M., Drube W.

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EN

We report valence states of ions in La_{0.7}Ce_{0.3}MnO_3 thin films grown by a reactive dc magnetron sputtering. The measurements were performed by means of high-energy X-ray photoelectron spectroscopy using synchrotron radiation. It was found that Ce ion in the compound is either in tetravalent or trivalent chemical state, manganese is in divalent, trivalent and tetravalent states, while La ion existing in oxide and hydroxide chemical species is in trivalent state.

Refine search results

Magnetoresistive Properties of Manganite-Based Heterojunctions

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

Phase Separation and Microwave Response of Epitaxial and Polycrystalline Manganite Films

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

Growth and Investigation of Heterostructures Based on Multiferroic BiFeO_3

Valence States of Metal Ions in La_{0.7}Ce_{0.3}MnO_3 Thin Films