Boosting Coercivity of 3D Printed Hard Magnets through Nano-Modification of the Powder Feedstock.

The demand for strong, compact permanent magnets essential for the energy transition drives innovation in magnet manufacturing. Additive manufacturing, particularly Powder Bed Fusion of metals using a laser beam (PBF-LB/M), offers potential for near-net-shaped Nd-Fe-B permanent magnets but often falls short compared to conventional methods. A less explored strategy to enhance these magnets is feedstock modification with nanoparticles.

Photomechanical Laser Fragmentation of IrO Microparticles for the Synthesis of Active and Redox-Sensitive Colloidal Nanoclusters.

Pulsed laser fragmentation of microparticles (MPs) in liquid is a synthesis method for producing high-purity nanoparticles (NPs) from virtually any material. Compared with laser ablation in liquids (LAL), the use of MPs enables a fully continuous, single-step synthesis of colloidal NPs. Although having been employed in several studies, neither the fragmentation mechanism nor the efficiency or scalability have been described.

Nanoparticle Additivation Effects on Laser Powder Bed Fusion of Metals and Polymers-A Theoretical Concept for an Inter-Laboratory Study Design All Along the Process Chain, Including Research Data Management.

In recent years, the application field of laser powder bed fusion of metals and polymers extends through an increasing variability of powder compositions in the market. New powder formulations such as nanoparticle (NP) additivated powder feedstocks are available today. Interestingly, they behave differently along with the entire laser powder bed fusion (PBF-LB) process chain, from flowability over absorbance and microstructure formation to processability and final part properties.

Impact of Ligands on Structural and Optical Properties of Ag Nanoclusters.

A ligand exchange strategy has been employed to understand the role of ligands on the structural and optical properties of atomically precise 29 atom silver nanoclusters (NCs). By ligand optimization, ∼44-fold quantum yield (QY) enhancement of Ag(BDT)(DHLA) NCs ( = 1-6) was achieved, where BDT and DHLA refer to 1,3-benzene-dithiol and dihydrolipoic acid, respectively. High-resolution mass spectrometry was used to monitor ligand exchange, and structures of the different NCs were obtained through density functional theory (DFT).

In situ structural kinetics of picosecond laser-induced heating and fragmentation of colloidal gold spheres.

Fragmentation of colloidal 54 nm gold nanoparticles by picosecond laser pulses is recorded by time-resolved X-ray scattering, giving access to structural dynamics down to a 80 ps resolution. Lattice temperature and energy dissipation have been quantified to verify that the maximum applied fluence of 1800 J m heats up the particles close to boiling. Already within 30 ns, particles with significantly lower particle sizes of 2 to 3 nm are detected, which hints towards an ultrafast process either by a thermal phase explosion or Coulomb instability.

Kinetically-controlled laser-synthesis of colloidal high-entropy alloy nanoparticles.

The single-step incorporation of multiple immiscible elements into colloidal high-entropy alloy (HEA) nanoparticles has manifold technological potential, but it continues to be a challenge for state-of-the-art synthesis methods. Hence, the development of a synthesis approach by which the chemical composition and phase of colloidal HEA nanoparticles can be controlled could lead to a new pool of nanoalloys with unparalleled functionalities. Herein, this study reports the single-step synthesis of colloidal CoCrFeMnNi HEA nanoparticles with targeted equimolar stoichiometry and diameters less than 5 nm by liquid-phase, ultrashort-pulsed laser ablation of the consolidated and heat-treated micropowders of the five constituent metals.

Synergism between Specific Halide Anions and pH Effects during Nanosecond Laser Fragmentation of Ligand-Free Gold Nanoparticles.

Gold nanoclusters (AuNCs) with diameters smaller than 3 nm are an emerging field of research because they possess interesting optical properties, such as photoluminescence. However, to date, it is still difficult to distinguish whether these properties originate from the cores of the nanoparticles or from the adsorbates on their surfaces. Hence, there is a high demand for ligand-free, ultra-small particles because they make it possible to study ligand and core effects separately.