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| Main Authors: | , , , , , , , , , , , , , |
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| Format: | Preprint |
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2025
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2502.02402 |
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| _version_ | 1866917421184450560 |
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| author | Nouchokgwe, Youri Fedorova, Natalya S. Biswas, Pranab Kovacova, Veronika Gorican, Ivana Drmovsek, Silvo Mukherjee, Binayak Prah, Uros Nataf, Guillaume F. Granzow, Torsten Guennou, Mael Ursic, Hana Iniguez-Gonzalez, Jorge Defay, Emmanuel |
| author_facet | Nouchokgwe, Youri Fedorova, Natalya S. Biswas, Pranab Kovacova, Veronika Gorican, Ivana Drmovsek, Silvo Mukherjee, Binayak Prah, Uros Nataf, Guillaume F. Granzow, Torsten Guennou, Mael Ursic, Hana Iniguez-Gonzalez, Jorge Defay, Emmanuel |
| contents | State-of-the-art electrocaloric cooling prototypes rely on the conventional electrocaloric effect of ferroelectric lead scandium tantalate (PbSc0.5Ta0.5O3, PST), which peaks near room temperature. Here, we demonstrate that A-site calcium doping in highly ordered PST modifies its phase transitions and enables precise tuning of the electrocaloric response. The transition temperature shifts down to 258 K and up to 319 K, depending on Ca concentration. Calorimetry under electric field, electrical polarization loops, and piezoresponse force microscopy reveal the emergence of an intermediate antiferroelectric phase stabilized for Ca $\geq$ 2\%. These results are supported by first-principles calculations. We observe a conventional electrocaloric effect for Ca $\leq$ 2\% and an inverse electrocaloric effect at higher doping ($\geq$ 2\%). Under an applied field of 110 kV cm$^{-1}$, Ca-doped PST exhibits an adiabatic temperature change of 2 K over a range from 263 K to 353 K. Such Ca-doped PST compounds could be used to expand the temperature range of PST below the freezing point of water. Our results offer a pathway to cascaded electrocaloric cooling devices with extended operating spans. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2502_02402 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Tunable electrocaloric effect in lead scandium tantalate through calcium doping Nouchokgwe, Youri Fedorova, Natalya S. Biswas, Pranab Kovacova, Veronika Gorican, Ivana Drmovsek, Silvo Mukherjee, Binayak Prah, Uros Nataf, Guillaume F. Granzow, Torsten Guennou, Mael Ursic, Hana Iniguez-Gonzalez, Jorge Defay, Emmanuel Materials Science State-of-the-art electrocaloric cooling prototypes rely on the conventional electrocaloric effect of ferroelectric lead scandium tantalate (PbSc0.5Ta0.5O3, PST), which peaks near room temperature. Here, we demonstrate that A-site calcium doping in highly ordered PST modifies its phase transitions and enables precise tuning of the electrocaloric response. The transition temperature shifts down to 258 K and up to 319 K, depending on Ca concentration. Calorimetry under electric field, electrical polarization loops, and piezoresponse force microscopy reveal the emergence of an intermediate antiferroelectric phase stabilized for Ca $\geq$ 2\%. These results are supported by first-principles calculations. We observe a conventional electrocaloric effect for Ca $\leq$ 2\% and an inverse electrocaloric effect at higher doping ($\geq$ 2\%). Under an applied field of 110 kV cm$^{-1}$, Ca-doped PST exhibits an adiabatic temperature change of 2 K over a range from 263 K to 353 K. Such Ca-doped PST compounds could be used to expand the temperature range of PST below the freezing point of water. Our results offer a pathway to cascaded electrocaloric cooling devices with extended operating spans. |
| title | Tunable electrocaloric effect in lead scandium tantalate through calcium doping |
| topic | Materials Science |
| url | https://arxiv.org/abs/2502.02402 |