Research papers of the month
Use the force
A large electric field may be used to drive a ferroelectric phase transition in order to pump heat, but these electrocaloric (EC) effects can be destructive, leading to breakdown. The present paper demonstrates that the ferroelectric phase transition in BaTiO3 (BTO) can be driven using hydrostatic pressure instead of an electric field. This type of barocaloric (BC) effect should now be studied in a wide range of ferroelectric materials, in order to optimise such materials for energy efficient cooling applications with no greenhouse gases.
Figure:EC and BC effects of opposite sign in BTO. The operating temperature range is larger for the BC effects because a ceramic sample was used instead of a single crystal.
E. Stern-Taulats, P. Lloveras, M. Barrio, E. Defay, M. Egilmez, A. Planes, J. Ll. Tamarit, Ll. Mañosa, N. D. Mathur and X. Moya, "Inverse barocaloric effects in ferroelectric BaTiO3 ceramics", APL Materials 4, 091102 (2016).