Origin of negative electrocaloric effect in Pnma-type antiferroelectric perovskites

Abstract

Anomalous electrocaloric effect (ECE) with decreasing temperature upon application of an electric field is known to occur in antiferroelectrics (AFEs), and previous understanding refers to the field-induced canting of electric dipoles if there is no phase transitions. Here, we use a first-principle-based method to study the ECE in Nd-substituted BiFeO3 (BNFO) perovskite solid solutions, which has the Pnma-type AFE ground state. We demonstrate another scenario to achieve and explain anomalous ECE, emphasizing that explicit consideration of octahedral tiltings is indispensable for a correct understanding. This mechanism may be general for AFEs for which the antipolar mode is not the primary order parameter. We also find that the negative ECE can reach a large magnitude in BNFO.

References in corpus (5)

• Phase diagram of Pb(Zr,Ti)O3 solid solutions from first principles
• First-principles study of the multi-mode anti-ferroelectric transition of PbZrO3
• Order-disorder transition in the prototypical antiferroelectric PbZrO${}_3$
• Electrocaloric effects in the lead-free Ba(Zr,Ti)O${}_3$ relaxor ferroelectric from atomistic simulations
• Electrocaloric effects in multiferroics

Cited by in corpus (1)

• Negative electrocaloric effect in nonpolar phases of perovskite over wide range of temperature