Investigating the impact of Nd3+ and V5+ Co‐doping on the dielectric response and microstructure of CaCu3Ti4O12 ceramics

Abstract A series of Ca 1‐ x Nd x Cu 3 Ti 4‐ y V y O 12 ( x = y = 0.0, 0.06, 0.08, 0.10) ceramics were synthesized using solid‐state reaction method. Incorporating Nd 3+ and V 5+ ions led to enhanced dielectric permittivity ( ε ′) and reduced dielectric loss (tan δ ). X‐ray diffraction data confirmed successful formation of a single‐phase material without secondary phases. X‐ray Photoelectron Spectroscopy revealed that core level binding energies were consistent with expected oxidation states. SEM analysis indicated that co‐doping alters grain morphology from irregular to cubic/hexagonal, with dopant concentration controlling the size. At x = y = 0.08 and 0.10, the co‐doped ceramics exhibited colossal ( ε ′ > 4 × 10 4 ) with good stability and relatively low tan δ < 0.1 (1–10 kHz, room temperature). Complex impedance analysis showed increased grain boundary resistance ( R gb ), correlating with reduced dielectric loss. Activation energy analysis revealed that the grain boundary activation energy ( E gb ) reached up to 0.299 eV for NdV10, while the grain interior activation energy ( E g ) ranged from 0.080 to 0.145 eV across all samples, correlating higher E gb with lower tan δ , and a doping‐sensitive Internal Barrier Layer Capacitor effect.