Giant negative electrocaloric effect in antiferroelectric PbZrO3 thin films in an ultra-low temperature range

2019 ◽  
Vol 7 (3) ◽  
pp. 617-621 ◽  
Author(s):  
Mengyao Guo ◽  
Ming Wu ◽  
Weiwei Gao ◽  
Buwei Sun ◽  
Xiaojie Lou
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Electrocaloric Effect ◽  
Temperature Range

Antiferroelectric thin films have demonstrated an excellent negative electrocaloric effect, and are potential candidates for future refrigeration applications.

Sizable electrocaloric effect in a wide temperature range tuned by tensile misfit strain in BaTiO3 thin films

2011 ◽  
Vol 109 (12) ◽  
pp. 126102 ◽  
Author(s):  
X. Zhang ◽  
J. B. Wang ◽  
B. Li ◽  
X. L. Zhong ◽  
X. J. Lou ◽  
...  
Keyword(s):  
Thin Films ◽  
Wide Temperature Range ◽  
Misfit Strain ◽  
Electrocaloric Effect ◽  
Temperature Range

PERSISTENT PHOTOCONDUCTIVITY IN La0.7CaxBa1-xMnO3 THIN FILMS

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3786-3791 ◽  
Author(s):  
R. CAURO ◽  
J. C. GRENET ◽  
A. GILABERT ◽  
M. G. MEDICI
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Visible Light ◽  
Low Temperatures ◽  
Transport Mechanism ◽  
Persistent Photoconductivity ◽  
Temperature Range ◽  
Insulator Metal Transition ◽  
First Time

We report, for the first time, experiments of persistent photoconductivity (PPC) in thin films of manganese perovskites La 0.7 Ca 0.25 Ba 0.05 MnO 3 and La 0.7 Ca 0.2 Ba 0.1 MnO 3 showing a persistent decrease of a few percent of the resistance after illumination with visible light. These persistent photoinduced effects are seen only in a range of low temperatures (<25 K) well below the insulator-metal transition at respectively T c=173 K and T c=120 K. In this low temperature range, the transport mechanism is rather of activated hopping type regime.

Leakage mechanism of (Ba0.7Sr0.3)TiO3 thin films in the low-temperature range

2002 ◽  
Vol 81 (25) ◽  
pp. 4817-4819 ◽  
Author(s):  
Hao Yang ◽  
Kun Tao ◽  
Bin Chen ◽  
Xianggang Qiu ◽  
Bo Xu ◽  
...  
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Temperature Range ◽  
Leakage Mechanism

scholarly journals Adjustable giant negative electrocaloric effect in Pb1+xZrO3 thin films

2021 ◽  
Author(s):  
Yi Ye ◽  
Fengzhen Huang ◽  
Lin Lei ◽  
Lin Liu ◽  
Shuo Yan ◽  
...  
Keyword(s):  
Thin Films ◽  
Electric Field ◽  
Room Temperature ◽  
Sol Gel ◽  
Entropy Change ◽  
Interface Layer ◽  
Electrocaloric Effect ◽  
Temperature Range ◽  
Si Substrates ◽  
Pb Concentration

Abstract Electrocaloric effect (ECE) driven by electric field is suitable for implementation of built-in cooling in electronic devices. However, most of the known electrocaloric materials show low adiabatic temperature change ( ) near room temperature and usually require high electric field. Here, the investigation of ECE in Pb 1+x ZrO 3 (x=0, 0.1, 0.15) thin films, which were prepared on Pt/Ti/SiO 2 /Si substrates by sol-gel method, reveals that both the magnitude and the present temperature range of can be controlled by Pb concentration. Through increasing the dosage of PbO, decreased lead vacancies and enhanced interface layer are induced, which postpone the transition from antiferroelectrics to ferroelectrics of PbZrO 3 films under a given electric field ( E ), which thus controls the appearance temperature range of negative ECE. As a result, large isothermal entropy change ( and are observed in the temperature range from 260 K to 494 K, depending on the applied electric field and Pb concentration. Giant ECE ( , ~0.054) at room temperature (303 K) is obtained in Pb 1.1 ZrO 3 films under 460 kV/cm. This result provides a convenient method for modulating ECE of PbZrO 3 -based materials and will benefit its applications in cooling devices.

Giant Negative Electrocaloric Effect in Antiferroelectric La-modified PbZrO3 Thin Films within Wide Temperature Range

2021 ◽  
pp. 161192
Author(s):  
Wenping Geng ◽  
Dongwan Zheng ◽  
Xiaojun Qiao ◽  
Xiangjian Wang ◽  
Le Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Wide Temperature Range ◽  
Electrocaloric Effect ◽  
Temperature Range

Observation by HVEM of the martensite transformation and the superconducting transition in Nb3Sn

1988 ◽  
Vol 46 ◽  
pp. 788-789
Author(s):  
M. A. Kirk ◽  
M. C. Baker ◽  
B. J. Kestel ◽  
H. W. Weber
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Superconducting State ◽  
Martensite Transformation ◽  
Sputter Deposition ◽  
Diffusion Reaction ◽  
Solute Diffusion ◽  
Superconducting Transition ◽  
Twin Boundaries ◽  
Martensite Structure

It is well known that a number of compound superconductors with the A15 structure undergo a martensite transformation when cooled to the superconducting state. Nb3Sn is one of those compounds that transforms, at least partially, from a cubic to tetragonal structure near 43 K. To our knowledge this transformation in Nb3Sn has not been studied by TEM. In fact, the only low temperature TEM study of an A15 material, V3Si, was performed by Goringe and Valdre over 20 years ago. They found the martensite structure in some foil areas at temperatures between 11 and 29 K, accompanied by faults that consisted of coherent twin boundaries on {110} planes. In pursuing our studies of irradiation defects in superconductors, we are the first to observe by TEM a similar martensite structure in Nb3Sn.Samples of Nb3Sn suitable for TEM studies have been produced by both a liquid solute diffusion reaction and by sputter deposition of thin films.

scholarly journals Stabilization of Ferroelectric Phase in Highly Oriented Quinuclidinium Perrhenate (HQReO4) Thin Films

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2126
Author(s):  
Junyoung Lee ◽  
Woojun Seol ◽  
Gopinathan Anoop ◽  
Shibnath Samanta ◽  
Sanjith Unithrattil ◽  
...  
Keyword(s):  
Thin Films ◽  
Solution Process ◽  
Intermediate Temperature ◽  
Perovskite Oxide ◽  
Temperature Phase ◽  
Polar Phase ◽  
Practical Applications ◽  
Temperature Range ◽  
Potential Alternative ◽  
Temperature Window

The low-temperature processability of molecular ferroelectric (FE) crystals makes them a potential alternative for perovskite oxide-based ferroelectric thin films. Quinuclidinium perrhenate (HQReO4) is one such molecular FE crystal that exhibits ferroelectricity when crystallized in an intermediate temperature phase (ITP). However, bulk HQReO4 crystals exhibit ferroelectricity only for a narrow temperature window (22 K), above and below which the polar phase transforms to a non-FE phase. The FE phase or ITP of HQReO4 should be stabilized in a much wider temperature range for practical applications. Here, to stabilize the FE phase (ITP) in a wider temperature range, highly oriented thin films of HQReO4 were prepared using a simple solution process. A slow evaporation method was adapted for drying the HQReO4 thin films to control the morphology and the temperature window. The temperature window of the intermediate temperature FE phase was successfully widened up to 35 K by merely varying the film drying temperature between 333 and 353 K. The strategy of stabilizing the FE phase in a wider temperature range can be adapted to other molecular FE materials to realize flexible electronic devices.

Low temperature charge carrier hopping transport mechanism in vanadium oxide thin films grown using pulsed dc sputtering

2009 ◽  
Vol 94 (22) ◽  
pp. 222110 ◽  
Author(s):  
S. S. N. Bharadwaja ◽  
C. Venkatasubramanian ◽  
N. Fieldhouse ◽  
S. Ashok ◽  
M. W. Horn ◽  
...  
Keyword(s):  
Thin Films ◽  
Low Temperature ◽  
Charge Carrier ◽  
Vanadium Oxide ◽  
Transport Mechanism ◽  
Oxide Thin Films ◽  
Hopping Transport ◽  
Dc Sputtering ◽  
Pulsed Dc ◽  
Vanadium Oxide Thin Films

A novel low-temperature growth of uniform CuInS2 thin films and their application in selenization/sulfurization-free CuInS2 solar cells

2021 ◽  
Vol 26 ◽  
pp. 102050
Author(s):  
Mehdi Dehghani ◽  
Ershad Parvazian ◽  
Nastaran Alamgir Tehrani ◽  
Nima Taghavinia ◽  
Mahmoud Samadpour
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Low Temperature ◽  
Temperature Growth ◽  
Low Temperature Growth ◽  
Cuins2 Thin Films
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