Oleate-based hydrothermal preparation of CoFe.sub.2./sub.O.sub.4./sub. nanoparticles, and their magnetic properties with respect to particle size and surface coating

Repko, A.; Vejpravová, Jana; Vacková, Taťana; Zákutná, D.; Nižňanský, D.

doi:https://dx.doi.org/10.1016/j.jmmm.2015.04.090

Number of the records: 1

Oleate-based hydrothermal preparation of CoFe.sub.2./sub.O.sub.4./sub. nanoparticles, and their magnetic properties with respect to particle size and surface coating

1.

SYSNO ASEP	0448155
Document Type	J - Journal Article
R&D Document Type	Journal Article
Subsidiary J	Článek ve WOS
Title	Oleate-based hydrothermal preparation of CoFe₂O₄ nanoparticles, and their magnetic properties with respect to particle size and surface coating
Author(s)	Repko, A. (CZ) Vejpravová, Jana (FZU-D)_{RID, ORCID} Vacková, Taťana (UMCH-V)_RID Zákutná, D. (CZ) Nižňanský, D. (CZ)
Source Title	Journal of Magnetism and Magnetic Materials. - : Elsevier - ISSN 0304-8853 Roč. 390, Sep (2015), s. 142-151
Number of pages	10 s.
Language	eng - English
Country	NL - Netherlands
Keywords	superparamagnetism ; size effect ; monodisperse nanocrystals ; hydrothermal synthesis ; cobalt iron oxide ; titania
Subject RIV	BM - Solid Matter Physics ; Magnetism
R&D Projects	TE01020118 GA TA ČR - Technology Agency of the Czech Republic (TA ČR)
Institutional support	FZU-D - RVO:68378271 ; UMCH-V - RVO:61389013
UT WOS	000355141200024
EID SCOPUS	84928682112
DOI	10.1016/j.jmmm.2015.04.090
Annotation	hydrolysis of Co-Fe oleate in the presence of pentanol/octanol/toluene and water. The particle size (6 – 10 nm) was controlled by the composition of the organic solvent and temperature. Magnetic properties were then investigated with respect to the particle size and surface modification with citric acid or titanium dioxide. The as-prepared hydrophobic nanoparticles (coated by oleic acid) had a minimum inter-particle distance of 2.5 nm. Their apparent blocking temperature was 180 K, 280 K and 330 K for the particles with size of 6, 9 or 10.5 nm,respectively. Replacement of oleic acid on the surface by citric acid decreased inter-particle distance to less than 1 nm, and increased blocking temperature by ca. 10 K. Coating with titanium dioxide, supported by nitrilotri(methylphosphonic acid), caused increase of the particle spacing, and lowering of the blocking temperature by ca. 20 K.
Workplace	Institute of Physics
Contact	Kristina Potocká, potocka@fzu.cz, Tel.: 220 318 579
Year of Publishing	2016

Number of the records: 1