A research team at Northeastern University has developed Fe27Co4NiCu4Mo3Si3BYLaNd alloy powder using vacuum induction gas atomization (VIGA), subsequently formed via laser cladding. At an energy density of 168 J/mm², the alloy achieves 99.9% relative density with significantly suppressed thermal cracking. The material exhibits an average electromagnetic shielding effectiveness of 102 dB in the K-band (18-26.5 GHz), peaking at 120 dB at 20.5 GHz—double the military standard of 60 dB—while also demonstrating soft magnetic properties with a saturation magnetization of 177.3 emu/g and coercivity of 77 Oe. This superior performance arises from a multiphase synergistic mechanism involving α-Fe cores, boride networks, and nanoscale rare-earth compounds. The study offers a new pathway for developing electromagnetic compatibility materials for 5G and 6G communication infrastructure.