Magnetic and Electromagnetic Shielding Properties of AlCoCrFeNi High-Entropy Alloy Thin Films

The rapid advancement of electronic and telecommunication technologies has intensified electromagnetic pollution, driving the need for efficient electromagnetic interference (EMI) shielding materials. High-entropy alloys (HEAs), composed of multiple principal elements in near-equiatomic ratios, offer tuneable magnetic and electronic properties with high structural stability. In this work, we deposit an AlCoCrFeNi HEA thin film using magnetron sputtering. Grazing-incidence X-ray diffraction revealed distinct (110) reflections, confirming a crystalline body-centred cubic (bcc)-derived structure, while energy-dispersive X-ray spectroscopy verified uniform composition. The film exhibits ferromagnetism at room temperature, with a magnetic transition near 28 K. In addition to magnetic characterization, transport, magnetoresistance (MR), and Hall measurements were performed to explore the film’s electronic behaviour. The coexistence of ferromagnetism and metallic conductivity enhances magnetic and dielectric losses, achieving broadband EMI shielding efficiency above 20 dB across 8.2-12.4 GHz. These results demonstrate the strong potential of HEA thin films for advanced EMI shielding applications.