Ultrasonic measurement of the electrocaloric effect in KH2PO4

Electrocaloric effect in KH_{2}PO_{4} family crystals

“…crystals with the adiabatically applied electric field are shown in figures 4 and 5. The experimental data of [7] were obtained at T = 121 K, which was very close to the transition temperature of the sample used in the measurements. ♦ [20].…”

“…In the hydrogen bonded ferroelectrics of the KH 2 PO 4 (KDP) type, the electrocaloric effect was studied for relatively low fields only. Thus, it has been obtained that ∆T ≈ 0.04 K at E ≈ 4 kV/cm [5], ∆T ≈ 1 K at E ≈ 12 kV/cm [6], and ∆T ≈ 0.25 K at T c and E ≈ 1.2 kV/cm [7].…”

Electrocaloric effect in KH$_2$PO$_4$

“…The experimental behavior in the ferroelectric phase is not linear at E < 3 kV/cm because of the domains. The experimental data of [5] (fig. 12) were obtained at T = 121 K, which was very close to the transition temperature of the sample used in the measurements.…”

“…In cheaper and more readily available hydrogen bonded ferroelectrics of the KH 2 PO 4 (KDP) type the electrocaloric effect was studied for relatively low fields only. Thus, it has been obtained that ∆T ≈ 0.04 K at E ≈ 4 kV/cm [3], ∆T ≈ 1 K at E ≈ 12 kV/cm [4], and ∆T ≈ 0.25 K at T c and E ≈ 1.2 kV/cm [5]. The electrocaloric effect in KDP in high fields remains unexplored.…”

Electrocaloric and barocaloric effects in CsH2PO4 ferroelectric

“…In cheaper and more accessible KH 2 PO 4 (KDP) type ferroelectrics with hydrogen bonds, the EC effect has been investigated in relatively weak fields or not at all. In particular, in the KDP crystal there was achieved Δ𝑇 ec ≈ 0.04 K at the field strength 𝐸 ≈ 4 kV/cm [8], Δ𝑇 ec ≈ 1K at 𝐸 ≈ 12 kV/cm [9] and Δ𝑇 ≈ 0.25 K at temperature 𝑇 𝑐 at 𝐸 ≈ 1.2 kV/cm [10]. Calculations carried out in [11] based on the pseudospin model of a deformed KDP crystal show that the Δ𝑇 ec in this crystal can exceed 5 K.…”