Random Magnets

Random magnetic order as a broadband absorber

The project investigated microwave absorption in magnets with quenched disorder and random magnetic anisotropy, considering how dimensionality, exchange, local anisotropy and temperature determine the high-frequency response.

Research strands

• Theoretical and numerical analysis of absorption in one-, two- and three-dimensional random-anisotropy magnets.
• Scaling relations between magnetic structure and microwave response.
• Design of magnetic composites and multilayer absorbers.
• Extraction of complex permittivity and permeability from S-parameter measurements.
• Optimisation of reflection loss, absorber thickness and bandwidth.

Experimental programme

The experimental branch, developed with Jaume Calvo-de la Rosa, Antoni García-Santiago, Javier Tejada and UB collaborators, examined ceramic nanocomposites and functional absorber architectures. The programme culminated in recent work on ceramic nanocomposites with magnetic random anisotropy.

Applications

The results address radar-absorbing materials, electromagnetic shielding and the design of lightweight, tunable microwave absorbers.