Solvent Influence on the Magnetization and Phase of Fe-Ni Alloy Nanoparticles Generated by Laser Ablation in Liquids

Inna Y Khairani; Qiyuan Lin; Joachim Landers; Soma Salamon; Carlos Doñate-Buendía; Evguenia Karapetrova; Heiko Wende; Giovanni Zangari; Bilal Gökce

doi:10.3390/nano13020227

Solvent Influence on the Magnetization and Phase of Fe-Ni Alloy Nanoparticles Generated by Laser Ablation in Liquids

Nanomaterials (Basel). 2023 Jan 4;13(2):227. doi: 10.3390/nano13020227.

Authors

Inna Y Khairani¹, Qiyuan Lin², Joachim Landers³, Soma Salamon³, Carlos Doñate-Buendía¹, Evguenia Karapetrova⁴, Heiko Wende³, Giovanni Zangari², Bilal Gökce¹

Affiliations

¹ Chair of Materials Science and Additive Manufacturing, School of Mechanical Engineering and Safety Engineering, University of Wuppertal, 42119 Wuppertal, Germany.
² Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA 22903, USA.
³ Faculty of Physics and Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, 47057 Duisburg, Germany.
⁴ Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA.

Abstract

The synthesis of bimetallic iron-nickel nanoparticles with control over the synthesized phases, particle size, surface chemistry, and oxidation level remains a challenge that limits the application of these nanoparticles. Pulsed laser ablation in liquid allows the properties tuning of the generated nanoparticles by changing the ablation solvent. Organic solvents such as acetone can minimize nanoparticle oxidation. Yet, economical laboratory and technical grade solvents that allow cost-effective production of FeNi nanoparticles contain water impurities, which are a potential source of oxidation. Here, we investigated the influence of water impurities in acetone on the properties of FeNi nanoparticles generated by pulsed laser ablation in liquids. To remove water impurities and produce "dried acetone", cost-effective and reusable molecular sieves (3 Å) are employed. The results show that the Fe₅₀Ni₅₀ nanoparticles' properties are influenced by the water content of the solvent. The metastable HCP FeNi phase is found in NPs prepared in acetone, while only the FCC phase is observed in NPs formed in water. Mössbauer spectroscopy revealed that the FeNi nanoparticles oxidation in dried acetone is reduced by 8% compared to acetone. The high-field magnetization of Fe₅₀Ni₅₀ nanoparticles in water is the highest, 68 Am²/kg, followed by the nanoparticles obtained after ablation in acetone without water impurities, 59 Am²/kg, and acetone, 52 Am²/kg. The core-shell structures formed in these three liquids are also distinctive, demonstrating that a core-shell structure with an outer oxide layer is formed in water, while carbon external layers are obtained in acetone without water impurity. The results confirm that the size, structure, phase, and oxidation of FeNi nanoparticles produced by pulsed laser ablation in liquids can be modified by changing the solvent or just reducing the water impurities in the organic solvent.

Keywords: carbon shell; core-shell nanoalloys; hexagonal closed packed phase; iron-nickel alloy; laser synthesis of colloids; nickel ferrite.

Grants and funding

405553726/Deutsche Forschungsgemeinschaft