Cargando…

Effect of Particle Size on the Magnetic Properties of Ni Nanoparticles Synthesized with Trioctylphosphine as the Capping Agent

Magnetic cores of passive components are required to have low hysteresis loss, which is dependent on the coercive force. Since it is well known that the coercive force becomes zero at the superparamagnetic regime below a certain critical size, we attempted to synthesize Ni nanoparticles in a size-co...

Descripción completa

Detalles Bibliográficos
Autores principales: Ishizaki, Toshitaka, Yatsugi, Kenichi, Akedo, Kunio
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5224645/
https://www.ncbi.nlm.nih.gov/pubmed/28335300
http://dx.doi.org/10.3390/nano6090172
_version_ 1782493400278237184
author Ishizaki, Toshitaka
Yatsugi, Kenichi
Akedo, Kunio
author_facet Ishizaki, Toshitaka
Yatsugi, Kenichi
Akedo, Kunio
author_sort Ishizaki, Toshitaka
collection PubMed
description Magnetic cores of passive components are required to have low hysteresis loss, which is dependent on the coercive force. Since it is well known that the coercive force becomes zero at the superparamagnetic regime below a certain critical size, we attempted to synthesize Ni nanoparticles in a size-controlled fashion and investigated the effect of particle size on the magnetic properties. Ni nanoparticles were synthesized by the reduction of Ni acetylacetonate in oleylamine at 220 °C with trioctylphosphine (TOP) as the capping agent. An increase in the TOP/Ni ratio resulted in the size decrease. We succeeded in synthesizing superparamagnetic Ni nanoparticles with almost zero coercive force at particle size below 20 nm by the TOP/Ni ratio of 0.8. However, the saturation magnetization values became smaller with decrease in the size. The saturation magnetizations of the Ni nanoparticles without capping layers were calculated based on the assumption that the interior atoms of the nanoparticles were magnetic, whereas the surface-oxidized atoms were non-magnetic. The measured and calculated saturation magnetization values decreased in approximately the same fashion as the TOP/Ni ratio increased, indicating that the decrease could be mainly attributed to increases in the amounts of capping layer and oxidized surface atoms.
format Online
Article
Text
id pubmed-5224645
institution National Center for Biotechnology Information
language English
publishDate 2016
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-52246452017-03-21 Effect of Particle Size on the Magnetic Properties of Ni Nanoparticles Synthesized with Trioctylphosphine as the Capping Agent Ishizaki, Toshitaka Yatsugi, Kenichi Akedo, Kunio Nanomaterials (Basel) Article Magnetic cores of passive components are required to have low hysteresis loss, which is dependent on the coercive force. Since it is well known that the coercive force becomes zero at the superparamagnetic regime below a certain critical size, we attempted to synthesize Ni nanoparticles in a size-controlled fashion and investigated the effect of particle size on the magnetic properties. Ni nanoparticles were synthesized by the reduction of Ni acetylacetonate in oleylamine at 220 °C with trioctylphosphine (TOP) as the capping agent. An increase in the TOP/Ni ratio resulted in the size decrease. We succeeded in synthesizing superparamagnetic Ni nanoparticles with almost zero coercive force at particle size below 20 nm by the TOP/Ni ratio of 0.8. However, the saturation magnetization values became smaller with decrease in the size. The saturation magnetizations of the Ni nanoparticles without capping layers were calculated based on the assumption that the interior atoms of the nanoparticles were magnetic, whereas the surface-oxidized atoms were non-magnetic. The measured and calculated saturation magnetization values decreased in approximately the same fashion as the TOP/Ni ratio increased, indicating that the decrease could be mainly attributed to increases in the amounts of capping layer and oxidized surface atoms. MDPI 2016-09-13 /pmc/articles/PMC5224645/ /pubmed/28335300 http://dx.doi.org/10.3390/nano6090172 Text en © 2016 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Ishizaki, Toshitaka
Yatsugi, Kenichi
Akedo, Kunio
Effect of Particle Size on the Magnetic Properties of Ni Nanoparticles Synthesized with Trioctylphosphine as the Capping Agent
title Effect of Particle Size on the Magnetic Properties of Ni Nanoparticles Synthesized with Trioctylphosphine as the Capping Agent
title_full Effect of Particle Size on the Magnetic Properties of Ni Nanoparticles Synthesized with Trioctylphosphine as the Capping Agent
title_fullStr Effect of Particle Size on the Magnetic Properties of Ni Nanoparticles Synthesized with Trioctylphosphine as the Capping Agent
title_full_unstemmed Effect of Particle Size on the Magnetic Properties of Ni Nanoparticles Synthesized with Trioctylphosphine as the Capping Agent
title_short Effect of Particle Size on the Magnetic Properties of Ni Nanoparticles Synthesized with Trioctylphosphine as the Capping Agent
title_sort effect of particle size on the magnetic properties of ni nanoparticles synthesized with trioctylphosphine as the capping agent
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5224645/
https://www.ncbi.nlm.nih.gov/pubmed/28335300
http://dx.doi.org/10.3390/nano6090172
work_keys_str_mv AT ishizakitoshitaka effectofparticlesizeonthemagneticpropertiesofninanoparticlessynthesizedwithtrioctylphosphineasthecappingagent
AT yatsugikenichi effectofparticlesizeonthemagneticpropertiesofninanoparticlessynthesizedwithtrioctylphosphineasthecappingagent
AT akedokunio effectofparticlesizeonthemagneticpropertiesofninanoparticlessynthesizedwithtrioctylphosphineasthecappingagent