Large conventional and inverse electrocaloric effects in PbMg<sub>0.5</sub>W<sub>0.5</sub>O<sub>3</sub> multilayer capacitors above and below the Néel temperature
S. Hirose, Tomoyasu Usui, Takanobu Hiroto, B. Nair, Xavier Moya, N. D. Mathur
Abstract
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.