Effects of transition metal substitution doping on the structure and magnetic properties of biphenylene

This study employed first-principles calculations to comprehensively explore the structural, electronic, and magnetic properties of transition metal-doped biphenylene networks (BPNs). Initially, we optimized the most stable structures of biphenylene doped with various transition metals (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) and analysed their doping energies and electronic structures in detail. The results indicate that the introduction of transition metals induces varying degrees of spin polarization. Specifically, the Cr-doped BPN exhibits almost 100% spin polarization at the Fermi level, exhibiting the properties of a half-metal or a spin-gapless semiconductor. In contrast, V-doped, Mn-doped and Co-doped BPNs show incomplete spin polarization, and exhibit antiferromagnetic like properties on the C atom. Furthermore, an analysis of the energy differences between the spin states and the non-spin states confirmed the stability of spin states, providing theoretical support for the application of BPNs as a new class of magnetic materials. In summary, through transition metal doping, BPNs exhibit promising applications, particularly in the fields of magnetic storage and magnetic sensors, highlighting their significant potential.