scholarly journals Giant room temperature elastocaloric effect in metal-free thin-film perovskites

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Cheng Li ◽  
Yu Hui Huang ◽  
Jian-Jun Wang ◽  
Bo Wang ◽  
Yong Jun Wu ◽  
...  
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Room Temperature ◽  
Entropy Change ◽  
Stress Change ◽  
Chemical Doping ◽  
Metal Free ◽  
Organic Ferroelectrics ◽  
Potential Applications ◽  
Unit Stress

AbstractSolid-state refrigeration which is environmentally benign has attracted considerable attention. Mechanocaloric (mC) materials, in which the phase transitions can be induced by mechanical stresses, represent one of the most promising types of solid-state caloric materials. Herein, we have developed a thermodynamic phenomenological model and predicted extraordinarily large elastocaloric (eC) strengths for the (111)-oriented metal-free perovskite ferroelectric [MDABCO](NH4)I3 thin-films. The predicted room temperature isothermal eC ΔSeC/Δσ (eC entropy change under unit stress change) and adiabatic eC ΔTeC/Δσ (eC temperature change under unit stress change) for [MDABCO](NH4)I3 are −60.0 J K−1 kg−1 GPa−1 and 17.9 K GPa−1, respectively, which are 20 times higher than the traditional ferroelectric oxides such as BaTiO3 thin films. We have also demonstrated that the eC performance can be improved by reducing the Young’s modulus or enhancing the thermal expansion coefficient (which could be realized through chemical doping, etc.). We expect these discoveries to spur further interest in the potential applications of metal-free organic ferroelectrics materials towards next-generation eC refrigeration devices.

New Class of Microporous Materials: Porous Metal Phosphonate Thin Films

1996 ◽  
Vol 431 ◽  
Author(s):  
Lori A. Vermeulen ◽  
J. Pattanayak ◽  
Travis Fisher ◽  
Monica Hansford ◽  
Scott J. Burgmeyer
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Porous Metal ◽  
Porous Solids ◽  
New Class ◽  
Metal Phosphonates ◽  
Metal Phosphonate ◽  
Potential Applications ◽  
Shape Selective ◽  
Film Assembly

AbstractSolid state metal phosphonates (M(O3P-R-PO3) or M(O3P-R)2 (M = metal)) have layered structures where the metal atoms lie in planar sheets and the intervening R groups take up the interlamellar space. Microporous metal phosphonates can be prepared by reaction of the metal with a mixture of large and small phosphonates (M(O3P-LARGE)x(O3P-SMALL)2-x. The larger group acts as a pillar that holds the layers apart. Void spaces result from the presence of the smaller groups. The porous nature of these solids make them potential candidates for applications as sensors, size- and shape- selective catalysts, and chromatographic materials. Metal diphosphonates (M(O3P-R-PO3) can also be prepared one layer at a time on a surface, resulting in the construction of interesting superstructures that are not accessible through the solid state synthesis. For example, these superstructures can contain different components in sequential layers and may have applications in energy conversion, vectorial electron transport, and NLO devices. The preparation of microporous thin films would combine the desirable potential applications of the porous solids with the interesting parallel superstructures that can be prepared from the thin film assemblies. We report our progress toward the construction of microporous metal phosphonate thin films. The two methods that are currently being developed include: 1) phosphonate exchange of pre-assembled films, and 2) co-deposition of different large and small phosphonates during film assembly.

scholarly journals Study on fabrication method of composite oxide by room temperature atomic layer deposition

Impact ◽  
2020 ◽  
Vol 2020 (5) ◽  
pp. 16-18
Author(s):  
Fumihiko Hirose
Keyword(s):  
Thin Films ◽  
Atomic Layer Deposition ◽  
Graduate School ◽  
Room Temperature ◽  
Atomic Layer ◽  
Science And Engineering ◽  
Layer Deposition ◽  
Potential Applications ◽  
Properties Of Materials ◽  
Conducting Research

Thin films can be used to improve the surface properties of materials, enhancing elements such as absorption, abrasion resistance and corrosion resistance, for example. These thin films provide the foundation for a variety of applications in various fields and their applications depend on their morphology and stability, which is influenced by how they are deposited. Thin films can be deposited in different ways. One of these is a technology called atomic layer deposition (ALD). Professor Fumihiko Hirose, a scientist based at the Graduate School of Science and Engineering, Yamagata University, Japan, is conducting research on the room temperature ALD of oxide metals. Along with his team, Professor Hirose has developed a new and improved way of performing ALD to create thin films, and the potential applications are endless.

scholarly journals Metal free room temperature phosphorescence from molecular self-interactions in the solid state

2018 ◽  
Vol 6 (17) ◽  
pp. 4603-4626 ◽  
Author(s):  
Alessandra Forni ◽  
Elena Lucenti ◽  
Chiara Botta ◽  
Elena Cariati
Keyword(s):  
Solid State ◽  
Room Temperature ◽  
Organic Materials ◽  
Environmental Load ◽  
Room Temperature Phosphorescence ◽  
Metal Free ◽  
Low Toxicity

Purely organic materials showing solid state room temperature phosphorescence (RTP) are receiving an ever growing interest due to their low toxicity, cost and environmental load compared to their organometallic counterparts.

scholarly journals Highly Efficient Synthesis of Hindered 3-Azoindoles via Metal-Free C–H Functionalization of Indoles

Synthesis ◽  
2020 ◽  
Vol 52 (04) ◽  
pp. 574-580
Author(s):  
Nicolas Jacob ◽  
Lucas Guillemard ◽  
Joanna Wencel-Delord
Keyword(s):  
Steric Hindrance ◽  
Room Temperature ◽  
Efficient Synthesis ◽  
Atom Economy ◽  
Photochromic Compounds ◽  
Metal Free ◽  
Highly Efficient ◽  
Simple Protocol ◽  
Potential Applications

Although 3-azoindoles have recently emerged as an appealing family of photoswitch molecules, the synthesis of such compounds has been poorly covered in the literature. Herein a high-yielding and operationally simple protocol is reported allowing the synthesis of 3-azoindoles, featuring important steric hindrance around the azo motif. Remarkably, this C–H coupling is characterized by excellent atom economy and occurs under metal-free conditions, at room temperature, and within few minutes, delivering the expected products in excellent yields (quantitatively in most of the cases). Accordingly, a library of new molecules, with potential applications as photochromic compounds, is prepared.

scholarly journals Bi-continuous pattern formation in thin films via solid-state interfacial dealloying studied by multimodal characterization

2019 ◽  
Vol 6 (10) ◽  
pp. 1991-2002 ◽  
Author(s):  
Chonghang Zhao ◽  
Kim Kisslinger ◽  
Xiaojing Huang ◽  
Ming Lu ◽  
Fernando Camino ◽  
...  
Keyword(s):  
Thin Films ◽  
Energy Storage ◽  
Solid State ◽  
Pattern Formation ◽  
Nanostructured Thin Films ◽  
Biomedical Sensing ◽  
Potential Applications

Solid-state interfacial dealloying creates bi-continuous nanostructured thin films with 3D interconnected morphology, revealed by multimodal characterization, offering potential applications in catalysis, biomedical sensing and energy storage.

From Supramolecular Chirogenic Systems towards Prospective Functional Materials

2013 ◽  
Vol 699 ◽  
pp. 87-91 ◽  
Author(s):  
Victor Borovkov
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Supramolecular Chemistry ◽  
Functional Materials ◽  
Practical Application ◽  
Research Groups ◽  
Supramolecular Chirality ◽  
Potential Applications ◽  
Chiral Modification ◽  
Asymmetric Catalyst

This paper presents a succinct overview of recent advances of our research groups in the field of supramolecular chirogenic systems in the solution and in the solid state and consequent progress towards various functional materials having potential applications in different areas of science and technology. The phenomenon of supramolecular chirality, which is a smart combination of supramolecular chemistry and chiral science, is demonstrated with one of the most representative structural motifs amongst existing chirogenic systems, which is based upon the ethane-bridged bis-porphyrinoids. Further progress towards various functional materials is made upon preparation of different thin-films and nanostructures using the same bis-porphyrin architecture. For more practical application of functional materials chiral modification of metal surface is carried out resulting in effective asymmetric catalyst.

scholarly journals Spatially resolved solid-state reduction of graphene oxide thin films

2018 ◽  
Vol 5 (6) ◽  
pp. 1176-1184 ◽  
Author(s):  
Maria C. Morant-Miñana ◽  
Jonas Heidler ◽  
Gunnar Glasser ◽  
Hao Lu ◽  
Rüdiger Berger ◽  
...  
Keyword(s):  
Thin Films ◽  
Graphene Oxide ◽  
Solid State ◽  
Spatial Resolution ◽  
Room Temperature ◽  
Oxide Thin Films ◽  
State Reduction ◽  
Spatially Resolved ◽  
Solid State Reduction

Controlled reduction of GO thin-films at room temperature with spatial resolution simply by application of a voltage, without the intentional use of electrolytes, has been demonstrated.

A Review of the Influential Factors on the Ferroelectric Domain Structure in BiFeO3 Thin Films

2013 ◽  
Vol 544 ◽  
pp. 219-225 ◽  
Author(s):  
Yao Ting Huang ◽  
Xiu Li Fu ◽  
Xiao Hong Zhao ◽  
Wei Hua Tang
Keyword(s):  
Thin Films ◽  
Domain Structure ◽  
Room Temperature ◽  
Ferroelectric Domain ◽  
Influential Factors ◽  
Multiferroic Materials ◽  
Ferroelectric Domain Structure ◽  
Ferroelectric Domains ◽  
Potential Applications ◽  
Substrate Doping

BiFeO3 is a very promising multiferroic materials, which can present ferroelectric and antiferromagnetic properties at room temperature (Tn=643 K, Tc= 1103 K). Ferroelectric domains in BiFeO3 thin films have attracted much attention due to their potential applications in memory devices. The aim of this paper is to review the main factors which can influence the ferroelectric domain structure in BiFeO3 thin films, including substrate, doping and film thickness.

scholarly journals Giant room temperature electrocaloric effect in a layered hybrid perovskite ferroelectric: [(CH3)2CHCH2NH3]2PbCl4

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xitao Liu ◽  
Zhenyue Wu ◽  
Tong Guan ◽  
Haidong Jiang ◽  
Peiqing Long ◽  
...  
Keyword(s):  
Solid State ◽  
Electric Fields ◽  
Room Temperature ◽  
Structural Diversity ◽  
Entropy Change ◽  
Electrocaloric Effect ◽  
Hybrid Perovskite ◽  
First Order Phase Transition ◽  
Large Heat ◽  
First Order Phase

AbstractElectrocaloric effect driven by electric fields displays great potential in realizing highly efficient solid-state refrigeration. Nevertheless, most known electrocaloric materials exhibit relatively poor cooling performance near room temperature, which hinders their further applications. The emerging family of hybrid perovskite ferroelectrics, which exhibits superior structural diversity, large heat exchange and broad property tenability, offers an ideal platform. Herein, we report an exceptionally large electrocaloric effect near room temperature in a designed hybrid perovskite ferroelectric [(CH3)2CHCH2NH3]2PbCl4, which exhibits a sharp first-order phase transition at 302 K, superior spontaneous polarization (>4.8 μC/cm2) and relatively small coercive field (<15 kV/cm). Strikingly, a large isothermal entropy change ΔS of 25.64 J/kg/K and adiabatic temperature change ΔT of 11.06 K under a small electric field ΔE of 29.7 kV/cm at room temperature are achieved, with giant electrocaloric strengths of isothermal ΔS/ΔE of 0.86 J·cm/kg/K/kV and adiabatic ΔT/ΔE of 370 mK·cm/kV, which is larger than those of traditional ferroelectrics. This work presents a general approach to the design of hybrid perovskite ferroelectrics, as well as provides a family of candidate materials with potentially prominent electrocaloric performance for room temperature solid-state refrigeration.

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