scholarly journals Stacking Disorder by Design: Factors Governing the Polytypism of Silver Iodide upon Precipitation and Formation from the Superionic Phase

2019 ◽  
Vol 19 (4) ◽  
pp. 2131-2138
Author(s):  
Rachael L. Smith ◽  
Martin Vickers ◽  
Martin Rosillo-Lopez ◽  
Christoph G. Salzmann
Keyword(s):  
Silver Iodide ◽  
Superionic Phase ◽  
Design Factors ◽  
Stacking Disorder

scholarly journals Stacking Disorder by Design: Factors Governing the Polytypism of Silver Iodide upon Precipitation and Formation from the Superionic Phase

2018 ◽  
Author(s):  
Rachael L. Smith ◽  
Martin Vickers ◽  
Christoph Salzmann
Keyword(s):  
Silver Iodide ◽  
Memory Effects ◽  
Silver Cation ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Superionic Phase ◽  
Wide Range ◽  
Adsorption Processes ◽  
Diffraction Patterns ◽  
Stacking Disorder

Silver iodide (AgI) is used for a wide range of applications from photocatalysis and antimicrobial coatings to photography and ice nucleation. By fitting powder X-ray diffraction patterns with DIFFaX, we show that AgI displays a strong tendency to form stacking-disordered materials. Its polytypism is determined by the silver cation to iodide molar ratio during precipitation. Under iodide-rich conditions, fully hexagonal <i>b</i>-AgI is obtained whereas a maximal percentage of cubic stacking of 80% is obtained at a 1:2 molar ratio in the silver cation-rich regime. These findings are explained on the basis of a concentration-dependent competition between kinetically and thermodynamically-favored adsorption processes. Furthermore, the previously reported memory effects observed upon transforming hexagonal and cubic AgI to the high-temperature superionic phase and back are now followed quantitatively. We propose that the memory effects originate from excess ions at the surfaces of AgI crystals that stabilize the pyroelectricity of AgI associated with hexagonal stacking. The ability to ‘design’ the polytypism of AgI by tuning the precipitation conditions provides a first example where the stacking disorder of a material can be controlled in a continuous fashion. Future studies will clarify if this design principle can be applied to other materials as well.

scholarly journals Stacking Disorder by Design: Factors Governing the Polytypism of Silver Iodide upon Precipitation and Formation from the Superionic Phase

2018 ◽  
Author(s):  
Rachael L. Smith ◽  
Martin Vickers ◽  
Christoph Salzmann
Keyword(s):  
Silver Iodide ◽  
Memory Effects ◽  
Silver Cation ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Superionic Phase ◽  
Wide Range ◽  
Adsorption Processes ◽  
Diffraction Patterns ◽  
Stacking Disorder

Silver iodide (AgI) is used for a wide range of applications from photocatalysis and antimicrobial coatings to photography and ice nucleation. By fitting powder X-ray diffraction patterns with DIFFaX, we show that AgI displays a strong tendency to form stacking-disordered materials. Its polytypism is determined by the silver cation to iodide molar ratio during precipitation. Under iodide-rich conditions, fully hexagonal <i>b</i>-AgI is obtained whereas a maximal percentage of cubic stacking of 80% is obtained at a 1:2 molar ratio in the silver cation-rich regime. These findings are explained on the basis of a concentration-dependent competition between kinetically and thermodynamically-favored adsorption processes. Furthermore, the previously reported memory effects observed upon transforming hexagonal and cubic AgI to the high-temperature superionic phase and back are now followed quantitatively. We propose that the memory effects originate from excess ions at the surfaces of AgI crystals that stabilize the pyroelectricity of AgI associated with hexagonal stacking. The ability to ‘design’ the polytypism of AgI by tuning the precipitation conditions provides a first example where the stacking disorder of a material can be controlled in a continuous fashion. Future studies will clarify if this design principle can be applied to other materials as well.

Behavior of the low-frequency conductivity of silver iodide nanocomposites in the superionic phase transition region

2013 ◽  
Vol 55 (1) ◽  
pp. 175-180 ◽  
Author(s):  
T. Yu. Vergent’ev ◽  
E. Yu. Koroleva ◽  
D. A. Kurdyukov ◽  
A. A. Naberezhnov ◽  
A. V. Filimonov
Keyword(s):  
Phase Transition ◽  
Transition Region ◽  
Silver Iodide ◽  
Low Frequency ◽  
Superionic Phase ◽  
Superionic Phase Transition ◽  
Phase Transition Region

Disappearance of the Superionic Phase Transition in Sub-5 nm Silver Iodide Nanoparticles

Nano Letters ◽  
2017 ◽  
Vol 17 (9) ◽  
pp. 5273-5276 ◽  
Author(s):  
Takayuki Yamamoto ◽  
Hirokazu Kobayashi ◽  
Loku Singgappulige Rosantha Kumara ◽  
Osami Sakata ◽  
Kiyofumi Nitta ◽  
...  
Keyword(s):  
Phase Transition ◽  
Silver Iodide ◽  
Superionic Phase ◽  
Superionic Phase Transition

“Preparation of Single Crystalline Gold Films for ED Studies”

1972 ◽  
Vol 30 ◽  
pp. 634-635
Author(s):  
Joseph D. C. Peng
Keyword(s):  
Crystal Morphology ◽  
Diffraction Theory ◽  
Scattering Matrix ◽  
Vacuum Evaporation ◽  
Gold Films ◽  
Matrix Formulation ◽  
Silver Films ◽  
Single Crystalline ◽  
Grating Pattern ◽  
Stacking Disorder

The relative intensities of the ED spots in a cross-grating pattern can be calculated using N-beam electron diffraction theory. The scattering matrix formulation of N-beam ED theory has been previously applied to imperfect microcrystals of gold containing stacking disorder (coherent twinning) in the (111) crystal plane. In the present experiment an effort has been made to grow single-crystalline, defect-free (111) gold films of a uniform and accurately know thickness using vacuum evaporation techniques. These represent stringent conditions to be met experimentally; however, if a meaningful comparison is to be made between theory and experiment, these factors must be carefully controlled. It is well-known that crystal morphology, perfection, and orientation each have pronounced effects on relative intensities in single crystals.The double evaporation method first suggested by Pashley was employed with some modifications. Oriented silver films of a thickness of about 1500Å were first grown by vacuum evaporation on freshly cleaved mica, with the substrate temperature at 285° C during evaporation with the deposition rate at 500-800Å/sec.

Compositional Tuning of Negative Differential Resistance in Bulk Silver Iodide Memristor

2020 ◽  
Author(s):  
SMITA GAJANAN NAIK ◽  
Mohammad Hussain Kasim Rabinal
Keyword(s):  
Power Consumption ◽  
Negative Differential Resistance ◽  
Silver Iodide ◽  
Differential Resistance ◽  
Fast Response ◽  
Low Power Consumption ◽  
Switching Effect ◽  
Memory Switching ◽  
Bulk Silver ◽  
Emerging Memory

Electrical memory switching effect has received a great interest to develop emerging memory technology such as memristors. The high density, fast response, multi-bit storage and low power consumption are their...

Phase Lag of Tire Cornering Force

1989 ◽  
Vol 17 (3) ◽  
pp. 184-200 ◽  
Author(s):  
R. Hanada ◽  
T. Nagumo ◽  
T. Mashita
Keyword(s):  
Phase Lag ◽  
Design Elements ◽  
Radial Location ◽  
Radial Stiffness ◽  
Design Factors

Abstract Automobile handling can be greatly improved by reducing the phase lag of tire cornering force behind imposed distortion. We have shown experimentally that this lag is related to in-plane stiffness of the belt and to radial, lateral, and circumferential stiffnesses of the sidewall. While the cornering stiffness is related to the belt rigidity, either can be changed without affecting the sidewall stiffnesses. The cornering stiffness, for example, is sensitive to design factors such as tread compound and tread pattern. The radial, lateral, and circumferential sidewall stiffnesses, however, are mutually perpendicular at a given point in a tire, so they cannot be changed independently of each other. In order to reduce the phase lag of the cornering force, the lateral and circumferential stiffnesses must be increased with a minimum increase in radial stiffness. This can be done by either lowering the radial location of the maximum section width of the inflated tire or by proper changes in material and/or design elements of the sidewall.

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