Alternating magnetic field energy absorption in the dispersion of iron oxide nanoparticles in a viscous medium

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081723%3A_____%2F15%3A00450283" target="_blank" >RIV/68081723:_____/15:00450283 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/70883521:28610/15:43872962

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.jmmm.2014.08.096" target="_blank" >http://dx.doi.org/10.1016/j.jmmm.2014.08.096</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jmmm.2014.08.096" target="_blank" >10.1016/j.jmmm.2014.08.096</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Alternating magnetic field energy absorption in the dispersion of iron oxide nanoparticles in a viscous medium

Popis výsledku v původním jazyce

Magnetic iron oxide nanoparticles were obtained by a coprecipitation method in a controlled growth process leading to the formation of uniform highly crystalline nanoparticles with average size of 13 nm, which corresponds to the superparamagnetic state. Nanoparticles obtained are a mixture of single-phase nanoparticles of magnetite and maghemite as well as nanoparticles of non-stoichiometric magnetite. The subsequent annealing of nanoparticles at 300 degrees C in air during 6 h leads to the full transformation to maghemite. It results in reduced value of the saturation magnetization (from 56 emu g(-1) to 48 emu g(-1) but does not affect the healing ability of nanoparticles. A 2-7 wt% dispersion of as-prepared and annealed nanoparticles in glycerol provides high healing rate in alternating magnetic fields allowed for application in magnetic hyperthermia; however the value of specific loss power does not exceed 30 W g(-1). This feature of heat output is explained by the combined effect of magnetic interparticle interactions and the properties of the carrier medium. Nanoparticles coalesce during the synthesis and form aggregates showing ferromagnetic-like behavior with magnetization hysteresis, distinct sexes on Mossbauer spectrum, blocking temperature well about room temperature, which accounts for the higher energy barrier for magnetization reversal. At the same time, low specific heat capacity of glycerol intensifies heat transfer in the magnetic dispersion. However, high viscosity of glycerol limits the specific loss power value, since predominantly the Neel relaxation accounts for the absorption of AC magnetic field energy.

Název v anglickém jazyce

Alternating magnetic field energy absorption in the dispersion of iron oxide nanoparticles in a viscous medium

Popis výsledku anglicky

Magnetic iron oxide nanoparticles were obtained by a coprecipitation method in a controlled growth process leading to the formation of uniform highly crystalline nanoparticles with average size of 13 nm, which corresponds to the superparamagnetic state. Nanoparticles obtained are a mixture of single-phase nanoparticles of magnetite and maghemite as well as nanoparticles of non-stoichiometric magnetite. The subsequent annealing of nanoparticles at 300 degrees C in air during 6 h leads to the full transformation to maghemite. It results in reduced value of the saturation magnetization (from 56 emu g(-1) to 48 emu g(-1) but does not affect the healing ability of nanoparticles. A 2-7 wt% dispersion of as-prepared and annealed nanoparticles in glycerol provides high healing rate in alternating magnetic fields allowed for application in magnetic hyperthermia; however the value of specific loss power does not exceed 30 W g(-1). This feature of heat output is explained by the combined effect of magnetic interparticle interactions and the properties of the carrier medium. Nanoparticles coalesce during the synthesis and form aggregates showing ferromagnetic-like behavior with magnetization hysteresis, distinct sexes on Mossbauer spectrum, blocking temperature well about room temperature, which accounts for the higher energy barrier for magnetization reversal. At the same time, low specific heat capacity of glycerol intensifies heat transfer in the magnetic dispersion. However, high viscosity of glycerol limits the specific loss power value, since predominantly the Neel relaxation accounts for the absorption of AC magnetic field energy.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BM - Fyzika pevných látek a magnetismus

OECD FORD obor

—

Projekt

<a href="/cs/project/ED2.1.00%2F03.0111" target="_blank" >ED2.1.00/03.0111: Centrum polymerních systémů</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2015

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Magnetism and Magnetic Materials

ISSN

0304-8853

e-ISSN

—

Svazek periodika

374

Číslo periodika v rámci svazku

JAN

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

8

Strana od-do

508-515

Kód UT WoS článku

000344949000082

EID výsledku v databázi Scopus

2-s2.0-84907279771