<abstract xmlns="http://www.w3.org/1999/xhtml"> Polycrystalline bulk samples of double layered (DL) colossal magnetoresistive (CMR) manganites R1.2Sr1.8Mn2O7 (R = La, Pr, Sm) were prepared by sol-gel method to study the effect of size of lanthanide ion on their magnetotransport properties. The electrical resistivity of the samples was investigated in the temperature range of 70 K to 300 K at different magnetic fields. The samples LSMO and PSMO show insulator-to-metal transition (IMT) behavior, while SSMO sample exhibits insulating behavior in the entire temperature range with a very large value of resistivity. The insulator-to-metal transition temperature (TIM) decreases from 123 K (LSMO) to 90 K (PSMO) and disappears in SSMO sample. To explain the electrical transport above TIM, the temperature dependent resistivity data (T > TIM) of all the samples were fitted to the equations of different conduction models. The results indicate that the conduction at T > TIM is due to Mott variable range hopping (VRH) mechanism in the LSMO and PSMO samples, while Efros-Shkloskii (ES) type of VRH model dominates the conduction process in the SSMO sample. All the three samples show increasing magnetoresistance (MR) even below TIM and the maximum MR is shown by LSMO (39 % at 75 K, 3 T).</abstract>

Polycrystalline bulk samples of double layered (DL) colossal magnetoresistive (CMR) manganites R1.2Sr1.8Mn2O7 (R = La, Pr, Sm) were prepared by sol-gel method to study the effect of size of lanthanide ion on their magnetotransport properties. The electrical resistivity of the samples was investigated in the temperature range of 70 K to 300 K at different magnetic fields. The samples LSMO and PSMO show insulator-to-metal transition (IMT) behavior, while SSMO sample exhibits insulating behavior in the entire temperature range with a very large value of resistivity. The insulator-to-metal transition temperature (TIM) decreases from 123 K (LSMO) to 90 K (PSMO) and disappears in SSMO sample. To explain the electrical transport above TIM, the temperature dependent resistivity data (T > TIM) of all the samples were fitted to the equations of different conduction models. The results indicate that the conduction at T > TIM is due to Mott variable range hopping (VRH) mechanism in the LSMO and PSMO samples, while Efros-Shkloskii (ES) type of VRH model dominates the conduction process in the SSMO sample. All the three samples show increasing magnetoresistance (MR) even below TIM and the maximum MR is shown by LSMO (39 % at 75 K, 3 T).

Electrical transport and magnetoresistance of double layered CMR manganites R1.2Sr1.8Mn2O7(R = La, Pr, Sm)

Materials Science-Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Electrical transport and magnetoresistance of double layered CMR manganites RSrMnO(R = La, Pr, Sm)

Polycrystalline bulk samples of double layered (DL) colossal magnetoresistive (CMR) manganites R1.2Sr1.8Mn2O7 (R = La, Pr, Sm) were prepared by sol-gel method...

Electrical transport and magnetoresistance of double layered CMR manganites R_1.2Sr_1.8Mn₂O₇(R = La, Pr, Sm)

Published Online: Jul 26, 2017

Page range: 440 - 446

Received: Dec 07, 2016

Accepted: Mar 23, 2017

DOI: https://doi.org/10.1515/msp-2017-0048

Keywords
double layered manganites, electrical transport, magnetoresistance, variable range hopping, sol-gel process

© 2017

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Electrical transport and magnetoresistance of double layered CMR manganites R1.2Sr1.8Mn2O7(R = La, Pr, Sm)

Published Online: Jul 26, 2017

Page range: 440 - 446

Received: Dec 07, 2016

Accepted: Mar 23, 2017

DOI: https://doi.org/10.1515/msp-2017-0048

Keywordsdouble layered manganites, electrical transport, magnetoresistance, variable range hopping, sol-gel process

© 2017

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Electrical transport and magnetoresistance of double layered CMR manganites R_1.2Sr_1.8Mn₂O₇(R = La, Pr, Sm)

Keywords
double layered manganites, electrical transport, magnetoresistance, variable range hopping, sol-gel process