Superparamagnetism in Cobalt Nanoparticles Coated by Protective Gold Layer

• Authors: P. Hrubovčák , A. Zeleňáková , V. Zeleňák , J. Kováč
• Languages of publication: EN

Abstracts

EN

In this work we present the study on structural and magnetic properties of fine cobalt nanoparticles coated by protective gold layer synthetized by microemulsion method. Structural measurements (powder XRD, HRTEM) confirmed spherical shape of the particles, their nanocrystalline character and presence of individual Co and Au phases. Investigation of magnetic properties of the particles revealed superparamagnetic behavior at higher temperatures and magnetic hysteresis at low temperatures. Average magnetic moment of individual particle m_{p}~86.3μ_{B} was established. The critical temperature, below which the magnetic moments of the particles are blocked, was T_{B}=6 K. Investigation of magnetic relaxation processes via magnetic susceptibility, detected one maximum attributed to single relaxation process, present in the particles. Obtained data, interpreted in terms of Neél-Arrhenius and Vogel-Fulcher theoretical models, confirmed the presence of strong magnetic interparticle interactions.

Keywords

EN

75.40.Cx; 75.75.Fk; 68.37.Og

Discipline

• 68.37.Og: High-resolution transmission electron microscopy (HRTEM)
• 75.40.Cx: Static properties (order parameter, static susceptibility, heat capacities, critical exponents, etc.)
• 75.75.Fk: Domain structures in nanoparticles

• Publisher: Institute of Physics, Polish Academy of Sciences
• Journal: Acta Physica Polonica A
• Year: 2014
• Volume: 126
• Issue: 1
• Pages: 216-217

Dates

published

2014-07

Contributors

author

P. Hrubovčák

• Institute of Physics, Faculty of Sciences, P.J. Šafárik University, Park Angelinum 9, 041 54 Košice, Slovakia

author

A. Zeleňáková

• Institute of Physics, Faculty of Sciences, P.J. Šafárik University, Park Angelinum 9, 041 54 Košice, Slovakia

author

V. Zeleňák

• Department of Inorganic Chemistry, Faculty of Sciences, P.J. Šafárik University Moyzesova 11, 040 01 Košice, Slovakia

author

J. Kováč

• Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01 Kosice, Slovakia

References

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Identifiers

DOI

10.12693/APhysPolA.126.216