Synthesis, crystal structure and physical properties of ThV2Si2C containing V2C square lattices

Abstract

We report a new quaternary compound, ThV₂Si₂C, containing V₂C square nets that are sandwiched by Si sheets. The compound crystallizes in a CeCr₂Si₂C-type structure with cell parameters of a = b = 4.1008 Å and c = 5.4150 Å. Magnetic, electrical transport, and specific heat measurements confirm the Pauli paramagnetic metal behavior in ThV₂Si₂C, concomitant with low magnetoresistance. At temperatures below 2 K, a possible weak superconducting transition is found. First-principles calculations reveal that V-3d orbitals dominate the electronic states at around the Fermi energy. These states predominantly originate from the d_x²−y², d_z², and d_yz orbitals, defining the primarily anisotropic nature of conduction within the V₂Si₂C block. The differences in the orbital-dependent pairing among charge carriers within isomorphic compounds are discussed.