Microwave Absorption Properties of Spinel‐Structured Mg–ZnAl ₂ O ₄

This study investigates the structural, optical, dielectric, and electromagnetic absorption properties of spinel‐structured Mg–ZnAl 2 O 4 synthesized through a sol–gel technique. The structural analysis confirmed the presence of various phases, including MgO, ZnO, ZnAl 2 O 4 , and MgAl 2 O 4 , with an average crystallite size of approximately 88 nm. The material demonstrated a reflection loss of −71 dB at 14.02 GHz, indicating its potential for effective microwave absorption, with an effective absorption bandwidth of 3.66 GHz at a thickness of 5 mm. The optical band gap was determined to be 3.19 eV, lower than that of ZnAl 2 O 4 and MgAl 2 O 4 , suggesting enhanced microwave absorption capabilities. Dielectric characterization revealed a range of dielectric constants from 3.09 to 6.31 across the frequency range of 8 to 18 GHz. These findings highlight the promising application of Mg–ZnAl 2 O 4 in microwave absorption technologies due to its favorable structural and electromagnetic properties.