Pulsed Laser Ablation in Liquid medium (PLAL) has been recently proposed for the production of nanoparticles (NPs), due to the excellent experimental flexibility of the technique and its "green" character. Different attempts have been realised to grow various kind of nanoparticles, showing that NP properties critically depend on experimental conditions [1-3]. Because of the complexity of physical processes involved in the synthesis, in-depth studies are required to allow a full control on NPs shape, size, composition and crystallinity. This capability could be reached in principle through an accurate choice of experimental parameters, which appears particularly appealing for FePt NPs, since colloidal solutions of L10-FePt NPs with size of a few nanometers can be hardly prepared by chemical synthesis methods. We have produced colloidal solutions of FePt nanoparticles by PLAL and performed a complete characterisation of the NPs samples by X-Ray Diffraction, Transmission Electron Microscopy (TEM), Alternating Gradient Force Magnetometry and SQUID Magnetometry. We have tested different laser parameters (wavelength, fluence, laser repetition rate, spot size) and solvents (water, ethanol and acetone), with the aim of correlating the experimental parameters with NP characteristics. NPs with spherical shape, variable size (in the range 1-100 nm) and composition (Fe3Pt, FePt and FePt3) have been obtained. We have demonstrated the possibility to obtain core-shell NPs by a suitable choice of the experimental conditions and evidenced that the PLAL technique determines a prevalence of the Pt-rich composition (FePt3) in the larger nanoparticles and a more balanced ratio in the smaller ones. Coherently with TEM analysis, NPs show a superparamagnetic or ferromagnetic behaviour depending on NP size. [1] V. Amendola et al., Phys. Chem. Chem. Phys. 11, 3805 (2009). [2] G.W. Yang, Prog. Mater. Sci 52, 648 (2007). [3] G. Cristoforetti et al., Appl. Surf. Sci. 258, 3289 (2012).
Colloidal solutions of FePt nanoparticles by Pulsed Laser Ablation in liquid medium
Nasi L;Casoli F;Cristoforetti G;Tognoni E;Albertini F;Cabassi R;Fabbrici S;Bertoni G
2012
Abstract
Pulsed Laser Ablation in Liquid medium (PLAL) has been recently proposed for the production of nanoparticles (NPs), due to the excellent experimental flexibility of the technique and its "green" character. Different attempts have been realised to grow various kind of nanoparticles, showing that NP properties critically depend on experimental conditions [1-3]. Because of the complexity of physical processes involved in the synthesis, in-depth studies are required to allow a full control on NPs shape, size, composition and crystallinity. This capability could be reached in principle through an accurate choice of experimental parameters, which appears particularly appealing for FePt NPs, since colloidal solutions of L10-FePt NPs with size of a few nanometers can be hardly prepared by chemical synthesis methods. We have produced colloidal solutions of FePt nanoparticles by PLAL and performed a complete characterisation of the NPs samples by X-Ray Diffraction, Transmission Electron Microscopy (TEM), Alternating Gradient Force Magnetometry and SQUID Magnetometry. We have tested different laser parameters (wavelength, fluence, laser repetition rate, spot size) and solvents (water, ethanol and acetone), with the aim of correlating the experimental parameters with NP characteristics. NPs with spherical shape, variable size (in the range 1-100 nm) and composition (Fe3Pt, FePt and FePt3) have been obtained. We have demonstrated the possibility to obtain core-shell NPs by a suitable choice of the experimental conditions and evidenced that the PLAL technique determines a prevalence of the Pt-rich composition (FePt3) in the larger nanoparticles and a more balanced ratio in the smaller ones. Coherently with TEM analysis, NPs show a superparamagnetic or ferromagnetic behaviour depending on NP size. [1] V. Amendola et al., Phys. Chem. Chem. Phys. 11, 3805 (2009). [2] G.W. Yang, Prog. Mater. Sci 52, 648 (2007). [3] G. Cristoforetti et al., Appl. Surf. Sci. 258, 3289 (2012).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
