Formation of Fe-Ni Nanoparticle Strands in Macroscopic Polymer Composites: Experiment and Simulation

Magnetic-field-induced strand formation of ferromagnetic Fe-Ni nanoparticles in a PMMA-matrix is correlated with the intrinsic material parameters, such as magnetization, particle size, composition, and extrinsic parameters, including magnetic field strength and viscosity. Since various factors can influence strand formation, understanding the composite fabrication process that maintains the strand lengths of Fe-Ni in the generated structures is a fundamental step in predicting the resulting structures. Hence, the critical dimensions of the strands (length, width, spacing, and aspect ratio) are investigated in the experiments and simulated via different intrinsic and extrinsic parameters. Optimal parameters were found by optical microscopy measurements and finite-element simulations using COMSOL for strand formation of Fe50Ni50 nanoparticles. The anisotropic behavior of the aligned strands was successfully characterized through magnetometry measurements. Compared to the unaligned samples, the magnetically aligned strands exhibit enhanced conductivity, increasing the current by a factor of 1000.

Automated summary

The formation of Fe-Ni nanoparticle strands induced by magnetic fields in a PMMA matrix is influenced by intrinsic and extrinsic parameters, and understanding and optimizing these parameters in the fabrication process is crucial for predicting resulting structures. The critical dimensions of the strands were investigated through experiments and simulations, with optimal parameters found for strand formation of Fe50Ni50 nanoparticles. Characterization of the aligned strands' anisotropic behavior was successfully achieved through magnetometry measurements.