Dielectric properties and energy storage performance of lead-free strontium calcium titanate (Sr_0.60Ca_0.40)TiO₃ thick films

This work demonstrates the fabrication, characterization, and energy storage capacity of high calcium-doped strontium titanate thick films (Sr_0.60Ca_0.40TiO₃) for the first time. The thick films were fabricated using the screen-printing technique and densified using uniaxial pressing. The effect of densification on the structural, morphological, and surface chemical compositional of the materials was studied. The densified thick film revealed a notable frequency stability of dielectric permittivity (ε′) ≈ 198 with a low dielectric loss tangent (tanδ) in the order of 10^− 3 between 100 Hz and 1 MHz and was characterized by slim P-E loops signifying its paraelectric nature. A high energy recovery density (U_e) of 4.1 J/cm³ and a high energy efficiency of 96% were simultaneously reached.