Large conventional and inverse electrocaloric effects in PbMg0.5W0.5O3 multilayer capacitors above and below the Néel temperature

Abstract

Bulk PbMg _0.5 W _0.5 O _3 (PMW) is an antiferroelectric in which an electric field of 12 V μ m ^−1 is sufficient to initiate a nominally reversible transition to a dipole-aligned (ferroelectric) phase if operating just below the Néel temperature T _N , near room temperature (Li et al 2021 Adv. Funct. Mater. 31 2101176). Here we describe multilayer capacitors (MLCs) of PMW that permit 27 V µ m ^−1 to be applied without breakdown. Below T _N , nominally reversible driving of the partial (full) antiferroelectric–ferroelectric (AF–FE) transition over a wide (narrow) range of temperatures yields large inverse electrocaloric (EC) effects that peak at Δ T _j ∼ –2.6 K when applying 25 V μ m ^−1 at 293 K (Δ T _j denotes directly measured temperature jumps). Above T _N , nominally reversible driving of the partial (full) paraelectric–ferroelectric (PE–FE) transition yields large conventional EC effects that peak at Δ T _j ∼ +5.2 K when applying 25 V μ m ^−1 at 302 K. This good EC performance near room temperature implies that MLCs of PMW could be exploited in prototype EC coolers.

Keywords

• electrocaloric effects
• antiferroelectric
• multilayer capacitors