Kondo-like Behavior in Lightly Gd-Doped Manganite CaMnO3
Tomislav Ivek1, Matija Čulo1, Nikolina Novosel1
1Institut za fiziku, Bijenička cesta 46, HR-10000 Zagreb, Croatia.
Nanomaterials (Basel, Switzerland)
|June 11, 2025
Summary
This study investigates manganese oxides, Ca1-xGdxMnO3, revealing metallic behavior with resistivity upturns and negative magnetoresistance. Findings suggest Kondo-like scattering and percolation of ferromagnetic metallic regions in an antiferromagnetic matrix.
Area of Science:
- Condensed matter physics
- Materials science
- Solid-state chemistry
Background:
- Manganese oxides (manganites) exhibit complex phase diagrams with competing ferromagnetic (FM) metallic and antiferromagnetic (AFM) insulating states.
- Colossal magnetoresistance is a hallmark of manganites, but conductivity mechanisms remain debated.
- Understanding these mechanisms is crucial for materials science and condensed matter physics.
Purpose of the Study:
- Investigate the conductivity mechanism in poorly explored Ca1-xGdxMnO3 manganites.
- Analyze magnetotransport properties in relation to magnetic structure.
- Elucidate the interplay between magnetic phases and electrical transport.
Main Methods:
- Magnetotransport measurements were performed on sintered nanocrystalline Ca1-xGdxMnO3 samples (x=0.05, 0.10).
- Measurements spanned temperatures from 2 K to 300 K and magnetic fields up to 16 T.
- Analysis focused on resistivity and magnetoresistance behavior.
Main Results:
- Both compounds displayed metallic behavior at low temperatures, characterized by a resistivity upturn.
- A significant negative magnetoresistance was observed.
- The observed phenomena were consistent with Kondo-like scattering and percolation effects.
Conclusions:
- The study provides insights into the complex conductivity mechanisms in Ca1-xGdxMnO3.
- Kondo-like scattering on Gd impurities and percolation of FM metallic regions are proposed as key factors.
- These findings contribute to the fundamental understanding of manganite physics.
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