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Tuning Magnetoconductivity in LaMnO3 NPs through Cationic Vacancy Control.
Antonio Hernando1,2,3,4, M Luisa Ruiz-González5, Omar Diaz1,5
1Departamento de Ingeniería, Universidad Antonio de Nebrija, Pirineos 55, 28940 Madrid, Spain.
Nanomaterials (Basel, Switzerland)
|May 27, 2023
Summary
Introducing La-Mn vacancies in lanthanum manganite (LaMnO3) nanoparticles significantly alters conductivity. Below 200 K, high magnetoconductivity arises from electron hopping between Mn3+ and Mn4+ ions, influenced by spin alignment.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Lanthanum manganite (LaMnO3) exhibits complex electrical and magnetic properties.
- Defect engineering, specifically introducing vacancies, is a key strategy to tune material characteristics.
Purpose of the Study:
- To investigate the impact of La-Mn vacancies on the conductivity of LaMnO3 nanoparticles.
- To elucidate the mechanism behind the observed magnetoconductivity at low temperatures.
Main Methods:
- Synthesis of LaMnO3 nanoparticles with controlled La-Mn vacancies.
- Electrical conductivity measurements as a function of temperature and applied magnetic field.
- Analysis of activation energy and its correlation with magnetization.
Main Results:
- LaMnO3 nanoparticles with La-Mn vacancies maintain insulating behavior at high temperatures.
- Significant high magnetoconductivity is observed below 200 K.
- Activation energy shows a linear decrease with the square of reduced magnetization, vanishing at saturation.
Conclusions:
- Electron hopping between Mn3+ and Mn4+ ions is the dominant conductivity mechanism below the Curie temperature in these doped nanoparticles.
- Applied magnetic fields enhance conductivity by increasing electron hopping probability through spin alignment.
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