TY - JOUR

T1 - Effect of air annealing on properties of maghemite nanoparticles produced by radiation-chemical method

AU - Ilves, V.

AU - Pizúrová, N.

AU - Korusenko, P.

AU - Sokovnin, S.

AU - Balezin, M.

AU - Gerasimov, A.

AU - Uimin, M.

AU - Zuev, M.

AU - Vasin, A.

N1 - The work was supported with the Czech Science Foundation, project № 21–31852J, and with the Russian Science Foundation, project № 22-19-00239.

PY - 2023/8/1

Y1 - 2023/8/1

N2 - Amorphous-crystalline nanoparticles (NPles) of maghemite (γ-Fe2O3) were successfully prepared by a radiation-chemical method using a precursor-heptahydrate of iron (II) sulfate. Synthesized NPles were quasi-spherical agglomerates 200–300 nm in size with an uneven surface covered with thin, porous, randomly oriented, elongated plates of irregular shape, with sharp vertices. The amorphous component of NPles included ultra-fine NPles maghemite about 2 nm in size. Stepwise annealing of the original nanopowder (NP) in air showed a phase transformation of NPles along the following path: maghemite + amorph (RT-150 °C) →amorph (200–500 °C) →hematite (570–1050 °C). The hematite NP produced after annealing at a temperature of 575 °C showed good texture characteristics: the specific surface area (SSA) increased from 21 to 36.8 m2/g, the pore volume increased from 0.04 to 0.15 cm3/g, while maintaining the particle nanosize of not more than 38 nm. X-ray photoelectron spectroscopy (XPS) showed the presence of the following elements on the surface of the synthesized NPles –S, C, O, Fe and N (N only in the original sample S0) and increased O–Fe bond with an increase in annealing temperature. The paramagnetic properties of the studied NPles indicate the prospect of their use as contrast agents in magnetic resonance imaging (MRI).

AB - Amorphous-crystalline nanoparticles (NPles) of maghemite (γ-Fe2O3) were successfully prepared by a radiation-chemical method using a precursor-heptahydrate of iron (II) sulfate. Synthesized NPles were quasi-spherical agglomerates 200–300 nm in size with an uneven surface covered with thin, porous, randomly oriented, elongated plates of irregular shape, with sharp vertices. The amorphous component of NPles included ultra-fine NPles maghemite about 2 nm in size. Stepwise annealing of the original nanopowder (NP) in air showed a phase transformation of NPles along the following path: maghemite + amorph (RT-150 °C) →amorph (200–500 °C) →hematite (570–1050 °C). The hematite NP produced after annealing at a temperature of 575 °C showed good texture characteristics: the specific surface area (SSA) increased from 21 to 36.8 m2/g, the pore volume increased from 0.04 to 0.15 cm3/g, while maintaining the particle nanosize of not more than 38 nm. X-ray photoelectron spectroscopy (XPS) showed the presence of the following elements on the surface of the synthesized NPles –S, C, O, Fe and N (N only in the original sample S0) and increased O–Fe bond with an increase in annealing temperature. The paramagnetic properties of the studied NPles indicate the prospect of their use as contrast agents in magnetic resonance imaging (MRI).

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UR - https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=tsmetrics&SrcApp=tsm_test&DestApp=WOS_CPL&DestLinkType=FullRecord&KeyUT=001027058400001

U2 - 10.1016/j.ceramint.2023.05.080

DO - 10.1016/j.ceramint.2023.05.080

M3 - Article

VL - 49

SP - 25414

EP - 25426

JO - Ceramics International

JF - Ceramics International

SN - 0272-8842

IS - 15

ER -