start-ver=1.4
cd-journal=joma
no-vol=124
cd-vols=
no-issue=
article-no=
start-page=108400
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2021
dt-pub=202102
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Effect of ultrasonic irradiation on ƒÁ-Fe2O3 formation by co-precipitation method with Fe3+ salt and alkaline solution
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=The effect of ultrasonic irradiation on direct maghemite (ƒÁ-Fe2O3) preparation by a co-precipitation method with Fe3+ salt (Fe(NO3)3) and an excess amount of alkaline (KOH) solution without going through the conventional magnetite (Fe3O4) formation route was explored in comparison with impeller stirring. The preparation procedure for obtaining iron oxide nanoparticles was designed using the sequential processes of precipitation, decantation, drying and thermal dehydration, and ultrasonic irradiation or impeller stirring was done during the precipitation process. ƒÁ-ferric oxyhydroxide (ƒÁ-FeOOH) was partially formed in addition to ƒ¿-ferric oxyhydroxide (ƒ¿-FeOOH) and thermally dehydrated to ƒÁ-Fe2O3 and hematite (ƒ¿-Fe2O3) by ultrasonic-assisted co-precipitation of Fe3+ salt and the excess KOH solution, whereas only ƒ¿-FeOOH and ƒ¿-Fe2O3 were synthesized by impeller stirring. The difference between the products of the two methods was explained by the Lamer model associated with the nucleation and growth of FeOOH. Magnetization increased as the crystallite diameter decreased, which is estimated to facilitate partial formation of magnetic ƒÁ-Fe2O3. Magnetization was enhanced by a lower ultrasonic frequency due to the stronger shock wave induced by the cavitation effect.
en-copyright=
kn-copyright=

en-aut-name=KoizumiHayato
en-aut-sei=Koizumi
en-aut-mei=Hayato
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=UddinMd. Azhar
en-aut-sei=Uddin
en-aut-mei=Md. Azhar
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=KatoYoshiei
en-aut-sei=Kato
en-aut-mei=Yoshiei
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

affil-num=1
en-affil=Department of Material and Energy Science, Graduate School of Environmental and Life Science, Okayama University
kn-affil=

affil-num=2
en-affil=Department of Material and Energy Science, Graduate School of Environmental and Life Science, Okayama University
kn-affil=

affil-num=3
en-affil=Department of Material and Energy Science, Graduate School of Environmental and Life Science, Okayama University
kn-affil=
en-keyword=ƒÁ-Fe2O3
kn-keyword=ƒÁ-Fe2O3
en-keyword=Ultrasonic irradiation
kn-keyword=Ultrasonic irradiation
en-keyword=Impeller stirring
kn-keyword=Impeller stirring
en-keyword=ƒÁ-FeOOH
kn-keyword=ƒÁ-FeOOH
en-keyword=Co-precipitation method
kn-keyword=Co-precipitation method
END