Electrocaloric response in lanthanum-modified lead zirconate titanate ceramics

Abstract

Recent findings of a large electrocaloric (EC) effect in polymeric and inorganic ferroelectric materials open a potential possibility of development of solid-state cooling or heating devices of new generation with better energy efficiency that may be less harmful for the environment. We investigate by using direct measurements, the temperature and electric field dependence of the electrocaloric response in Pb1-xLax(ZryTi1-y)1-x/4O3 bulk ceramics (PLZT) with x=0.06 and 0.12. Here, the properties of the EC response were probed in a part of the PLZT composition phase diagram with low y=0.40 composition, in which the EC effect was not previously studied. Measurement results show the existence of the sizeable EC response in 12/40/60 PLZT sample with the EC temperature change (ΔTEC) of 2.92 K at 430 K and 80 kV/cm. This value exceeds previously obtained ΔTEC values in relaxor ferroelectric x/65/35 PLZT compositions and rivaling the best EC response in lead magnesium niobate-lead titanate ceramics. The electrocaloric responsivity (ΔT/ΔE) value of 0.41x10 -6 Km/V determined at a lower electric field of 20 kV/cm and 410 K is comparable to those observed in other perovskite ferroelectrics. *

Electrocaloric Effect in PZT Thick Film for the Cooling Device Applications

“…4). The fourth order polynomial fitting to the P(T )E data has been used to extract the polarization as a function of temperature, P(T ) [4,5]. show the electrocaloric parameters T and S values for PZT thick film with respect to temperature calculated at different electric fields.…”

“…Solid state cooling devices have various fields of applications for example temperature regulation in electronic devices and also in on-chip cooling devices [1,3]. Theoretical analysis infers that the cooling devices which are performed on ECE have higher energy conversion efficiency than of vapour compressors [4]. The ECE effect also presents the advantage that less complex components and control are required than other technologies due to the application of external electric fields [4,5].…”

“…Theoretical analysis infers that the cooling devices which are performed on ECE have higher energy conversion efficiency than of vapour compressors [4]. The ECE effect also presents the advantage that less complex components and control are required than other technologies due to the application of external electric fields [4,5]. Under the application of external electric field, this effect is a significant way for the cooling device applications in the technological fields such as regulation in temperature for electronic devices and sensors and on-chip cooling.…”

“…where, C p is specific heat capacity, polarization is denoted by P and ρ is the density of the material [4,5]. Electrocaloric properties of ferroelectric materials have been investigated in the present study for cooling device applications.…”

“…Fig 4. Temperature dependent P-E hysteresis loop of grown PZT thick film at a particular frequency of 1 kHz…”