scholarly journals Large Negative Photoresistivity in Amorphous NdNiO3 Film

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1411
Author(s):  
Alexandr Stupakov ◽  
Tomas Kocourek ◽  
Natalia Nepomniashchaia ◽  
Marina Tyunina ◽  
Alexandr Dejneka
Keyword(s):  
Energy Density ◽  
Optical Absorption ◽  
Power Density ◽  
Room Temperature ◽  
Amorphous Film ◽  
Amorphous Films ◽  
Metal Insulator ◽  
Wide Range ◽  
Potential Applications

A significant decrease in resistivity by 55% under blue lighting with ~0.4 J·mm−2 energy density is demonstrated in amorphous film of metal-insulator NdNiO3 at room temperature. This large negative photoresistivity contrasts with a small positive photoresistivity of 8% in epitaxial NdNiO3 film under the same illumination conditions. The magnitude of the photoresistivity rises with the increasing power density or decreasing wavelength of light. By combining the analysis of the observed photoresistive effect with optical absorption and the resistivity of the films as a function of temperature, it is shown that photo-stimulated heating determines the photoresistivity in both types of films. Because amorphous films can be easily grown on a wide range of substrates, the demonstrated large photo(thermo)resistivity in such films is attractive for potential applications, e.g., thermal photodetectors and thermistors.

Interface motion during recrystallization of amorphous NiSi2

1990 ◽  
Vol 48 (4) ◽  
pp. 524-525
Author(s):  
J. L. Batstone ◽  
D.A. Smith
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Amorphous Film ◽  
Nucleation And Growth ◽  
Recrystallization Process ◽  
Amorphous Films ◽  
Interface Motion ◽  
Si Substrates ◽  
Spherical Caps ◽  
Crystal Interfaces

Recrystallization of amorphous NiSi2 involves nucleation and growth processes which can be studied dynamically in the electron microscope. Previous studies have shown thatCoSi2 recrystallises by nucleating spherical caps which then grow with a constant radial velocity. Coalescence results in the formation of hyperbolic grain boundaries. Nucleation of the isostructural NiSi2 results in small, approximately round grains with very rough amorphous/crystal interfaces. In this paper we show that the morphology of the rccrystallizcd film is dramatically affected by variations in the stoichiometry of the amorphous film.Thin films of NiSi2 were prepared by c-bcam deposition of Ni and Si onto Si3N4, windows supported by Si substrates at room temperature. The base pressure prior to deposition was 6 × 107 torr. In order to investigate the effect of stoichiomctry on the recrystallization process, the Ni/Si ratio was varied in the range NiSi1.8-2.4. The composition of the amorphous films was determined by Rutherford Backscattering.

Room-Temperature Ceramic Nanocoating Using Nanosheet Deposition Technique

2013 ◽  
Vol 2013 (CICMT) ◽  
pp. 000014-000018 ◽  
Author(s):  
M. Osada ◽  
T. Sasaki
Keyword(s):  
Room Temperature ◽  
Organic Molecules ◽  
Structural Diversity ◽  
Layer By Layer ◽  
Precise Control ◽  
Langmuir Blodgett ◽  
Wide Range ◽  
Potential Applications ◽  
Layer Assembly ◽  
Selection Of

We present a novel procedure for ceramic nanocoating using oxide nanosheet as a building block. A variety of oxide nanosheets (such as Ti1−δO2, MnO2 and perovsites) were synthesized by delaminating appropriate layered precursors into their molecular single sheets. These nanosheets are exceptionally rich in both structural diversity and electronic properties, with potential applications including conductors, semiconductors, insulators, and ferromagnets. Another attractive aspect is that nanosheets can be organized into various nanoarchitectures by applying solution-based synthetic techniques involving electrostatic layer-by-layer assembly and Langmuir-Blodgett deposition. It is even possible to tailor superlattice assemblies, incorporating into the nanosheet galleries with a wide range of materials such as organic molecules, polymers, and inorganic/metal nanoparticles. Sophisticated functionalities or paper-like devices can be designed through the selection of nanosheets and combining materials, and precise control over their arrangement at the molecular scale.

scholarly journals Comparative Investigation of Non-halogenated Imidazolium and Phosphonium-based Surface-Active Ionic Liquids as Electrolyte for Supercapacitors

2021 ◽  
Author(s):  
Preeti Jain ◽  
Oleg N. Antzutkin
Keyword(s):  
Ionic Liquids ◽  
Energy Density ◽  
Specific Capacitance ◽  
Power Density ◽  
High Energy ◽  
High Energy Density ◽  
Equivalent Series Resistance ◽  
Imidazolium Cations ◽  
Wide Range ◽  
Surface Active

<p>We report a comparative analysis of non-halogenated surface-active ionic liquids (SAILs), which consists of the surface-active anion, 2-ethylhexyl sulfate, and the phosphonium, and imidazolium cations <i>i.e.,</i> tetrabutylphosphonium ([P<sub>4444</sub>]<sup>+</sup>), trihexyl(tetradecyl)phosphonium ([P<sub>66614</sub>]<sup>+</sup>), and 1-methyl-3-hexylimidazolium ([C<sub>6</sub>C<sub>1</sub>IM]<sup>+</sup>). We explored the thermal and electrochemical properties, <i>i.e.</i>, degradation, melting and crystallization temperatures, and ionic conductivity of this new class of IL. These SAILs were tested as an electrolyte in a multi-walled carbon nanotubes (MWCNTs)-based supercapacitor at various temperatures from 253 to 373 K. The electrochemical performance of different SAILs by varying the cationic core as a function of temperature were compared, in the same MWCNT-based supercapacitor. We found that the supercapacitor cell with [C<sub>6</sub>C<sub>1</sub>IM][EHS] shown high specific capacitance (<i>C<sub>elec</sub></i> in F g<sup>-1</sup>), a high energy density (<i>E</i> in Wh kg<sup>-1</sup>), and a high power density (<i>P</i> in kW kg<sup>-1</sup>) when compared to those for the other SAILs <i>i.e.</i> [P<sub>4444</sub>][EHS], [P<sub>66614</sub>][EHS], and [N<sub>8888</sub>][EHS] at all temperatures. The supercapacitor with an MWCNT-based electrode and [C<sub>6</sub>C<sub>1</sub>IM][EHS], [P<sub>4444</sub>][EHS], and [P<sub>66614</sub>][EHS] as an electrolyte showed a specific capacitance of 148, 90, and 47 F g<sup>-1</sup> (at the scan rate of 2 mV s<sup>-1</sup>) with an energy density of 82, 50, and 26 Wh kg<sup>-1</sup> (at 2 mV s<sup>-1</sup>) respectively, at 298 K. The temperature effect can be seen by the three to four-fold increase in the specific capacitance of the cell and the energy density values, <i>i.e.</i>, 290, 198, and 114 F g<sup>-1</sup> (at 2 mV s<sup>-1</sup>) and 161, 110, and 63 Wh kg<sup>-1</sup> (at 2 mV s<sup>-1</sup>), respectively, at 373 K. This study reveals that these new SAILs specifically [C<sub>6</sub>C<sub>1</sub>IM][EHS] and [P<sub>4444</sub>][EHS] can potentially be used as electrolytes in the wide range of temperature. The solution resistance (<i>R<sub>s</sub></i>), charge transfer resistance (<i>R<sub>ct</sub></i>), and equivalent series resistance (ESR) also decreased with an increase in temperature for all SAILs as electrolytes. These new SAILs can explicitly be used for high-temperature (wide range of temperature) electrochemical applications, such as efficient supercapacitors for high energy storage due to enhanced specific capacitance, energy, and power density at elevated temperatures. </p>

scholarly journals Comparative Investigation of Non-halogenated Imidazolium and Phosphonium-based Surface-Active Ionic Liquids as Electrolyte for Supercapacitors

2021 ◽  
Author(s):  
Preeti Jain ◽  
Oleg N. Antzutkin
Keyword(s):  
Ionic Liquids ◽  
Energy Density ◽  
Specific Capacitance ◽  
Power Density ◽  
High Energy ◽  
High Energy Density ◽  
Equivalent Series Resistance ◽  
Imidazolium Cations ◽  
Wide Range ◽  
Surface Active

<p>We report a comparative analysis of non-halogenated surface-active ionic liquids (SAILs), which consists of the surface-active anion, 2-ethylhexyl sulfate, and the phosphonium, and imidazolium cations <i>i.e.,</i> tetrabutylphosphonium ([P<sub>4444</sub>]<sup>+</sup>), trihexyl(tetradecyl)phosphonium ([P<sub>66614</sub>]<sup>+</sup>), and 1-methyl-3-hexylimidazolium ([C<sub>6</sub>C<sub>1</sub>IM]<sup>+</sup>). We explored the thermal and electrochemical properties, <i>i.e.</i>, degradation, melting and crystallization temperatures, and ionic conductivity of this new class of IL. These SAILs were tested as an electrolyte in a multi-walled carbon nanotubes (MWCNTs)-based supercapacitor at various temperatures from 253 to 373 K. The electrochemical performance of different SAILs by varying the cationic core as a function of temperature were compared, in the same MWCNT-based supercapacitor. We found that the supercapacitor cell with [C<sub>6</sub>C<sub>1</sub>IM][EHS] shown high specific capacitance (<i>C<sub>elec</sub></i> in F g<sup>-1</sup>), a high energy density (<i>E</i> in Wh kg<sup>-1</sup>), and a high power density (<i>P</i> in kW kg<sup>-1</sup>) when compared to those for the other SAILs <i>i.e.</i> [P<sub>4444</sub>][EHS], [P<sub>66614</sub>][EHS], and [N<sub>8888</sub>][EHS] at all temperatures. The supercapacitor with an MWCNT-based electrode and [C<sub>6</sub>C<sub>1</sub>IM][EHS], [P<sub>4444</sub>][EHS], and [P<sub>66614</sub>][EHS] as an electrolyte showed a specific capacitance of 148, 90, and 47 F g<sup>-1</sup> (at the scan rate of 2 mV s<sup>-1</sup>) with an energy density of 82, 50, and 26 Wh kg<sup>-1</sup> (at 2 mV s<sup>-1</sup>) respectively, at 298 K. The temperature effect can be seen by the three to four-fold increase in the specific capacitance of the cell and the energy density values, <i>i.e.</i>, 290, 198, and 114 F g<sup>-1</sup> (at 2 mV s<sup>-1</sup>) and 161, 110, and 63 Wh kg<sup>-1</sup> (at 2 mV s<sup>-1</sup>), respectively, at 373 K. This study reveals that these new SAILs specifically [C<sub>6</sub>C<sub>1</sub>IM][EHS] and [P<sub>4444</sub>][EHS] can potentially be used as electrolytes in the wide range of temperature. The solution resistance (<i>R<sub>s</sub></i>), charge transfer resistance (<i>R<sub>ct</sub></i>), and equivalent series resistance (ESR) also decreased with an increase in temperature for all SAILs as electrolytes. These new SAILs can explicitly be used for high-temperature (wide range of temperature) electrochemical applications, such as efficient supercapacitors for high energy storage due to enhanced specific capacitance, energy, and power density at elevated temperatures. </p>

Aggregation-Induced Room Temperature Phosphorescent Carbonized Polymer Dots with Wide-Range Tunable Lifetime for Optical Multiplexing

2021 ◽  
Author(s):  
Jian Shen ◽  
Bin Xu ◽  
Zifei Wang ◽  
Jing Zhang ◽  
Weiguang Zhang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Information Storage ◽  
Luminescent Materials ◽  
Wide Range ◽  
Polymer Dots ◽  
Optical Multiplexing ◽  
Potential Applications

Optical multiplexing based on luminescent materials with tunable lifetime holds potential applications in information storage and security. However, most of these materials reported so far are still limited to microsecond...

scholarly journals Pulsed laser deposited CoFe2O4 thin films as supercapacitor electrodes

RSC Advances ◽  
2020 ◽  
Vol 10 (33) ◽  
pp. 19353-19359 ◽  
Author(s):  
S. M. Nikam ◽  
A. Sharma ◽  
M. Rahaman ◽  
A. M. Teli ◽  
S. H. Mujawar ◽  
...  
Keyword(s):  
Thin Films ◽  
Energy Density ◽  
Power Density ◽  
Electrode Material ◽  
Room Temperature ◽  
Cobalt Ferrite ◽  
Pulsed Laser ◽  
Different Temperatures ◽  
Ferrite Thin Films

Cobalt ferrite thin films were grown by PLD at different temperatures as an electrode material for supercapacitors. The films deposited at room temperature exhibited the best power density (3277 W kg−1) and energy density (17 W h kg−1) values.

Plasma Etching of PLT Thin Films and Bulk PLZT Using Fluorine- and Chlorine-Based Gases

1990 ◽  
Vol 200 ◽  
Author(s):  
M. R. Poor ◽  
A. M. Hurd ◽  
C. B. Fleddermann ◽  
A. Y. Wu
Keyword(s):  
Thin Films ◽  
Integrated Circuits ◽  
Substrate Temperature ◽  
Plasma Etching ◽  
Room Temperature ◽  
Removal Rate ◽  
Ceramic Film ◽  
Wide Range ◽  
Potential Applications ◽  
Silicon Based

ABSTRACTPotential applications for ferroelectric thin films include both electronic and optoelectronic devices. In order to integrate a large number of devices on a single ceramic film or to incorporate ceramic devices with silicon-based integrated circuits, suitable film patterning techniques must be developed. In this study, the use of plasma etching for device patterning of PLT thin films has been explored using a dc hollow cathode discharge with HCl and CF4 etching gases. At room temperature, no etching of material is discernable. As the substrate temperature is increased, however, relatively rapid etching takes place. Etch rates for PLT thin films as high as 6500 Å/hour were measured. Etching occurred in both chlorinated and fluorinated plasmas, but at considerably different rates. The etch rate is enhanced by a factor of six by using a combination of HCl and CF4 in the plasma. After etching, the stoichiometry of the film, measured by energy dispersive spectroscopy (EDS), varied greatly with changes in substrate temperature. Although the removal rate for each element is different, all traces of lead, titanium, and lanthanum can be removed from the substrate over a wide range of plasma etching conditions.

Nanoparticles and Films Formed by Pulsed Laser Irradiation on the CeO2 Target in the Liquid

2005 ◽  
Vol 475-479 ◽  
pp. 3843-3846
Author(s):  
Jiwei Chen ◽  
Jing Yang ◽  
Jian She Lian
Keyword(s):  
Energy Density ◽  
Laser Irradiation ◽  
Power Density ◽  
Pulsed Laser ◽  
Ceo2 Nanoparticles ◽  
Formation Mechanisms ◽  
Nanocrystalline Films ◽  
Amorphous Films ◽  
Pulsed Laser Irradiation

The irradiation of a Nd-YAG pulsed laser on the CeO2 target in water was investigated. The CeO2 nanoparticles sized of 20-80 nm were formed in water, while the power density was larger than 32 kJ/cm2. The nanocrystalline films with grain sized of 50-150 nm were formed on the target with the energy density of 20 kJ/cm2-25 kJ/cm2. Finally, the amorphous films were formed with the energy density of 6 kJ/cm2-15 kJ/cm2. The formation mechanisms of the nanoparticles and the films were discussed.

A new O3-type layered oxide cathode with high energy/power density for rechargeable Na batteries

2015 ◽  
Vol 51 (22) ◽  
pp. 4693-4696 ◽  
Author(s):  
Haodong Liu ◽  
Jing Xu ◽  
Chuze Ma ◽  
Ying Shirley Meng
Keyword(s):  
Phase Transformation ◽  
Energy Density ◽  
Cathode Material ◽  
Power Density ◽  
High Energy ◽  
High Energy Density ◽  
Rate Performance ◽  
Layered Oxide ◽  
Oxide Cathode ◽  
Wide Range

A new O3–Na0.78Li0.18Ni0.25Mn0.583Ow is prepared as the cathode material for Na-ion batteries, delivering exceptionally high energy density and superior rate performance. No phase transformation happens through a wide range of sodium concentrations.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

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