Influence of Reaction Solvent on Crystallinity and Magnetic Properties of MnFe₂O₄Nanoparticles Synthesized by Thermal Decomposition

Abstract

This study reports the synthesis of three kinds of manganese-doped magnetic ferrite nanoparticles (MnFe 2 O 4 ) in benzyl ether, octyl ether, and 1-octadecene by a simple and low cost thermal decomposition method. It was found that benzyl ether results in a dramatic improvement in nanoparticle crystallinity owing to its stronger reducibility compared to octyl ether and 1-octadecene, as demonstrated by X-ray diffraction and TEM measurements. Raman spectroscopy detection also indicated that the reducing solvent of benzyl ether was in favor of forming magnetite-like structure ferrite, while maghemite-like structured ferrite was obtained in octyl ether and 1-octadecene. The saturation magnetization ( ) of MnFe 2 O 4 synthesized in benzyl ether was 85 emu/g [Fe], which was 3 and 5 times larger than MnFe 2 O 4 synthesized in octyl ether and 1-octadecene, respectively. The specific absorption rate (SAR) of MnFe 2 O 4 nanoparticles synthesized in benzyl ether was 574 W/g, while MnFe 2 O 4 nanoparticles synthesized in octyl ether and 1-octadecene have had much smaller SAR of 76 and 33 W/g, respectively. MnFe 2 O 4 nanoparticles synthesized in benzyl ether also exhibit higher relaxivity ( 2 = 207 mM −1 s −1 ) than those synthesized in octyl ether and 1-octadecene ( 2 = 65 and 22 mM −1 s −1 ). It was obvious that MnFe 2 O 4 nanoparticles synthesized in reducing benzyl ether have higher crystallinity and thus higher , SAR, and 2 values, which can serve as a better candidate for hyperthermia and magnetic resonance imaging.

The Metal Ion Release of Manganese Ferrite Nanoparticles: Kinetics, Effects on Magnetic Resonance Relaxivities, and Toxicity

“…Ethanol (20 mL) was added to precipitate the nanoparticles. After washing three times with ethanol and hexane, the nanoparticles were separated by centrifugation (8000 rpm/min) and dispersed in hexane. , …”

“…After washing three times with ethanol and hexane, the nanoparticles were separated by centrifugation (8000 rpm/min) and dispersed in hexane. 20,30 2.3.3. 18 nm MnFe 2 O 4 NP Synthesis.…”

“…After washing three times with ethanol and hexane, the nanoparticles were separated by centrifugation (8000 rpm/min) and dispersed in hexane. 20,30 The synthesized MFNPs were successfully dispersed in aqueous solution by surface modification with DHCA. 31 Typically, 50 mg of DHCA was dissolved in 6 mL of THF and heated to 50 °C under an argon flow.…”

Solvent Effects on Growth, Crystallinity, and Surface Bonding of Ge Nanoparticles

“…Finding a colloidal method to produce near-IR emitting Ge NPs using a simple reduction of GeI 2 without the presence of strong reducing agents would be beneficial for further research and upscaling. Solvent effects on crystallinity, shape, and size have already been explored for other NP systems including MnFe 2 O 4 , 33 ZnSe, 34 and Co 35 but not for Ge NPs. The aim of this work is two-fold: to find a simple route to alkyl-capped Ge NPs via microwave synthesis, and to investigate the effect solvent has on the surface structure and growth of Ge NPs.…”

Adaptive iron-based magnetic nanomaterials of high performance for biomedical applications

“…It should be noted that the reaction solvent might influence the magnetic properties of MnFe2O4 nanoparticles. For example, the solvent with stronger reducibility can result in significant improvement in crystallinity and saturation magnetization [105].…”