From MAX to MXene: Unveiling Robust Magnetism and Half-Metallicity in Cr2ZnC and Its Half-Metallic 2D Cr2C Through Ab-Initio Investigation

A first-principles investigation was conducted to characterize the novel Cr2ZnC MAX phase and its exfoliated MXene nanosheet, Cr2C. The study critically examines the effect of electron correlations on the bulk phase, revealing that the PBE+U framework, unlike standard PBE, yields a dramatically enhanced magnetic moment of 12.80 μB (vs. 1.88 μB), confirming the necessity of this approach for Cr-based carbides. The phase stability is confirmed through rigorous analysis of its thermodynamic, dynamic, and mechanical properties. For the derived 2D Cr2C, results confirm a robust half-metallic state with a total magnetic moment of 8.00 μB, characterized by a metallic spin-majority channel and a semiconducting spin-minority channel with a 2.41 eV direct gap, leading to near-ideal spin polarization. These combined features establish Cr2C as a highly promising candidate for next-generation spintronic applications and 2D magnetic devices requiring room-temperature stability.