Magnetic composites with nickel nanoparticles synthesized by the method of the electrical explosion of wire were prepared with acrylic copolymer containing 95 wt. % of butylacrylate and 5 wt. % of methacrylic acid. Two series of composites were made with Ni content covering the range from 5 to 90 wt. % and differing in the degree of aggregation. In one series of composites, the aggregates were irregularly shaped globules with dimensions varying in 1-40 μm range. In the other, chain-like fragments were observed. As expected, the saturation magnetization value of the composites showed a linear dependence on concentration but the coercive field was slightly higher for the aggregated case for a given concentration. Microwave absorption studies of the composites showed both strong zero field absorption and ferromagnetic resonance (FMR). The FMR results were different for the two types of samples; however, each set can be explained by taking into account the distribution of local magnetic fields due to random positions of the particles.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)