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

• Published in: JPhys Energy Vol. 5; no. 3; pp. 035009 - 35016
• Main Authors: Hirose, Sakyo, Usui, Tomoyasu, Hiroto, Takanobu, Nair, Bhasi, Moya, Xavier, Mathur, Neil D
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.07.2023
• Subjects: antiferroelectric; Antiferroelectricity; Capacitors; Coolers; Dipoles; Electric fields; electrocaloric effects; Ferroelectric materials; multilayer capacitors; Multilayers; Neel temperature; Room temperature; Temperature
• ISSN: 2515-7655
• DOI: 10.1088/2515-7655/acdc53

Bulk PbMg0.5W0.5O3 (PMW) is an antiferroelectric in which an electric field of 12 V μm−1 is sufficient to initiate a nominally reversible transition to a dipole-aligned (ferroelectric) phase if operating just below the Néel temperature TN, near room temperature (Li et al 2021 Adv. Funct. Mater.31 2101176). Here we describe multilayer capacitors (MLCs) of PMW that permit 27 V µm−1 to be applied without breakdown. Below TN, 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 ΔTj ∼ –2.6 K when applying 25 V μm−1 at 293 K (ΔTj denotes directly measured temperature jumps). Above TN, nominally reversible driving of the partial (full) paraelectric–ferroelectric (PE–FE) transition yields large conventional EC effects that peak at ΔTj ∼ +5.2 K when applying 25 V μm−1 at 302 K. This good EC performance near room temperature implies that MLCs of PMW could be exploited in prototype EC coolers.