Electrocaloric properties of lead-free ferroelectric ceramic near room temperature

Enhanced electrocaloric effect, energy storage density and pyroelectric response from a domain-engineered lead-free BaTi0.91Sn0.08Zr0.01O3 ferroelectric ceramic

“…The obtained results (Δ T , Δ S and ξ ) under 30 kV cm −1 are compared with other BT-based ceramics B-site substituted which are presented in Table 2. 3,16,59,66–72 The BTSZ ceramic exhibited an exceptional EC response due to the appearance the coexistence of multiple phases in this composition. The contribution of F–F transitions ( T R–O or T O–T ) actually led to an important ferroelectric intrinsic polarization, which can improve the Δ S due to the disordered/ordered polar dipoles.…”

“…Maxwell's relation was used to calculate the adiabatic change in temperature (Δ T ) and the corresponding entropy change (Δ S ) of the prepared ceramic, which are given in ref. 16 and 63 : where ρ and C p are, respectively, the density of our prepared ceramic (5.3 g cm −3 ) and the specific heat of the sample. 64 Fig.…”

“…2. 3,16,59,[66][67][68][69][70][71][72] The BTSZ ceramic exhibited an exceptional EC response due to the appearance the coexistence of multiple phases in this composition. The contribution of F-F transitions (T R-O or T O-T ) actually led to an important ferroelectric intrinsic polarization, which can improve the DS due to the disordered/ ordered polar dipoles.…”

“…, the rhombohedral–orthorhombic phase transition ( T R–O = −90 °C), the orthorhombic–tetragonal phase transition ( T O–T = 0 °C) and the tetragonal–cubic phase transition ( T C = 120 °C). 14,15 However, it shows a low dielectric constant and poor energy storage properties that require strategies carried out by site engineering involving the substitution of Ba 2+ sites by Sr 2+ , Ca 2+ , Bi 3+ … and/or Ti 4+ sites by Hf 4+ , Zr 4+ , Sn 4+ …, 16–18 to improve these characteristics. Therefore, the substitution of BT can significantly increase their energy storage density.…”

“…14,15 However, it shows a low dielectric constant and poor energy storage properties that require strategies carried out by site engineering involving the substitution of Ba 2+ sites by Sr 2+ , Ca 2+ , Bi 3+ . and/or Ti 4+ sites by Hf 4+ , Zr 4+ , Sn 4+ ., [16][17][18] to improve these characteristics. Therefore, the substitution of BT can signicantly increase their energy storage density.…”