Electrically conductive and corrosion resistant MAX phases with superior electromagnetic wave shielding performance

Abstract

MAX phases have emerged as promising corrosion-resistant electromagnetic interference (EMI) shielding materials. Herein, four MAX phases: Ti3SiC2, Ti3AlC2, V0.5Cr1.5AlC, and Nb4AlC3, were synthesized via solid–liquid reactions. The electrical conductivities of Ti3SiC2, Ti3AlC2, V0.5Cr1.5AlC, and Nb4AlC3 are 14.7 × 103, 15.5 × 103, 5.1 × 103, 8.0 × 103 S/cm, respectively, and the corresponding average EMI shielding effectiveness values in the frequency of 18–26.5 GHz are 53.9, 69.2, 19.4, and 29.0 dB, respectively. Most importantly, these MAX phases are highly corrosion resistant under acidic conditions. Despite the exposure to the acidic environment and a slight decrease in the electrical conductivity, the corroded MAX phases exhibited excellent EMI shielding properties compared to the pristine MAX phases. Additional analysis showed that reflection was the primary EMI blocking mechanism. The study offers a guide for designing MAX phase ceramics that exhibit high EMI shielding performance in corrosive environments.