PHOSPHATE TUNGSTEN BRONZES — A NEW FAMILY OF QUASI-LOW-DIMENSIONAL METALLIC OXIDES

1993 ◽  
Vol 07 (23n24) ◽  
pp. 3937-3971 ◽  
Author(s):  
MARTHA GREENBLATT
Keyword(s):  
Single Crystals ◽  
Density Wave ◽  
Measurement Data ◽  
X Ray Diffraction ◽  
New Class ◽  
Metallic Oxides ◽  
New Family ◽  
Oxide Bronzes ◽  
Low Dimensional ◽  
Low Dimensional Materials

A brief introduction is presented on transition metal oxide bronzes and their relationship to the phosphate tungsten bronzes; the latter compounds are the major focus of this review. The phosphate tungsten bronzes (PTB) are a new class of quasi-low-dimensional materials which exhibit charge density wave (CDW) instabilities. The growth of single crystals and investigation of the physical properties including the temperature dependence of the electrical resistivity and magnetic susceptibility on oriented single crystals are discussed for selected members of the major families in the PTB’s. Correlation of the physical measurement data with structural properties, X-ray diffraction data and results of the theoretical band structure calculations are also presented.

scholarly journals Analysis of Electronic Properties from Magnetotransport Measurements on Ba(Fe1−xNix)2As2 Thin Films

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 630
Author(s):  
Ilya Shipulin ◽  
Stefan Richter ◽  
Aleena Anna Thomas ◽  
Kornelius Nielsch ◽  
Ruben Hühne ◽  
...  
Keyword(s):  
Single Crystals ◽  
Measurement Data ◽  
X Ray Diffraction ◽  
Crystalline Perfection ◽  
Ni Doping ◽  
Ginzburg Landau ◽  
Electronic Parameters ◽  
Electronic Heat ◽  
Good Agreement

We performed a detailed structural, magnetotransport, and superconducting analysis of thin epitaxial Ba(Fe1−xNix)2As2 films with Ni doping of x = 0.05 and 0.08, as prepared by pulsed laser deposition. X-ray diffraction studies demonstrate the high crystalline perfection of the films, which have a similar quality to single crystals. Furthermore, magnetotransport measurements of the films were performed in magnetic fields up to 9 T. The results we used to estimate the density of electronic states at the Fermi level, the coefficient of electronic heat capacity, and other electronic parameters for this compound, in their dependence on the dopant concentration within the framework of the Ginzburg–Landau–Abrikosov–Gorkov theory. The comparison of the determined parameters with measurement data on comparable Ba(Fe1−xNix)2As2 single crystals shows good agreement, which confirms the high quality of the obtained films.

scholarly journals Image polaritons in van der Waals crystals

Nanophotonics ◽  
2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Sergey G. Menabde ◽  
Jacob T. Heiden ◽  
Joel D. Cox ◽  
N. Asger Mortensen ◽  
Min Seok Jang
Keyword(s):  
Van Der Waals ◽  
Mirror Image ◽  
Propagation Loss ◽  
Strong Light ◽  
New Class ◽  
Close Proximity ◽  
Matter Interaction ◽  
Light Matter Interaction ◽  
Low Dimensional ◽  
Low Dimensional Materials

Abstract Polaritonic modes in low-dimensional materials enable strong light–matter interactions and the manipulation of light on nanometer length scales. Very recently, a new class of polaritons has attracted considerable interest in nanophotonics: image polaritons in van der Waals crystals, manifesting when a polaritonic material is in close proximity to a highly conductive metal, so that the polaritonic mode couples with its mirror image. Image modes constitute an appealing nanophotonic platform, providing an unparalleled degree of optical field compression into nanometric volumes while exhibiting lower normalized propagation loss compared to conventional polariton modes in van der Waals crystals on nonmetallic substrates. Moreover, the ultra-compressed image modes provide access to the nonlocal regime of light–matter interaction. In this review, we systematically overview the young, yet rapidly growing, field of image polaritons. More specifically, we discuss the dispersion properties of image modes, showcase the diversity of the available polaritons in various van der Waals materials, and highlight experimental breakthroughs owing to the unique properties of image polaritons.

scholarly journals Cascading transitions toward unconventional charge density wave states in the quasi-two-dimensional monophosphate tungsten bronze P4W16O56

IUCrJ ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 184-192
Author(s):  
Elen Duverger-Nédellec ◽  
Alain Pautrat ◽  
Kamil K. Kolincio ◽  
Laurence Hervé ◽  
Olivier Pérez
Keyword(s):  
Charge Density ◽  
Charge Density Wave ◽  
Density Wave ◽  
Chemical Vapour ◽  
Tungsten Bronze ◽  
X Ray Diffraction ◽  
Strong Electron ◽  
Electron Phonon Coupling ◽  
Wave States ◽  
Low Dimensional

Single crystals of the m = 8 member of the low-dimensional monophosphate tungsten bronzes (PO2)4(WO3)2m family were grown by chemical vapour transport technique and the high crystalline quality obtained allowed a reinvestigation of the physical and structural properties. Resistivity measurements revealed three anomalies at T C1 = 258 K, T C2 = 245 K and T C3 = 140 K, never observed until now. Parallel X-ray diffraction investigations showed a specific signature associated with three structural transitions, i.e. the appearance of different sets of satellite reflections below T C1, T C2 and T C3. Several harmonics of intense satellite reflections were observed, reflecting the non-sinusoidal nature of the structural modulations and a strong electron–phonon coupling in the material. These transitions could be associated with the formation of three successive unconventional charge density wave states.

ZnO Nanorods by a Simple Two Step Process

2013 ◽  
Vol 678 ◽  
pp. 223-226
Author(s):  
W. Bhagath Singh ◽  
Aleyamma Alexander ◽  
C.X. Joana May ◽  
Pricilla Mary ◽  
K. Thiyagarajan ◽  
...  
Keyword(s):  
Zno Nanorods ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Ir Detectors ◽  
Step Process ◽  
One Dimensional ◽  
Low Dimension ◽  
Nanostructured Metal Oxides ◽  
Low Dimensional ◽  
Low Dimensional Materials

Low-dimension materials such as nanobelts, nanowires and nanorods are being investigated for their superior properties and numerous applications. Among them, one-dimensional semiconductor ZnO, representing one of the most important low dimensional materials, finds its applications in many different fields such as sensors, solar cells, IR detectors, microelectronics, etc. Synthesis of nanostructures without any catalytic template, or using the self-catalytic behavior of the material would be of interest. In this work, ZnO nanorods have been synthesized by simple two step process without using any catalyst. This method provides an easy way to produce nanostructured metal oxides under normal conditions. The prepared samples were characterized by studying their structural, optical and morphological properties using X-Ray Diffraction, Photoluminescence and Scanning Electron Microscopy. The diameter of the prepared nanorods were around 20-30 nm¬. The room temperature Photoluminescence spectra of the ZnO nanorods shows a broad visible emission around 450–530 nm.

scholarly journals Determining the Degree of [001] Preferred Growth of Ni(OH)2 Nanoplates

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 991 ◽  
Author(s):  
Taotao Li ◽  
Ning Dang ◽  
Wanggang Zhang ◽  
Wei Liang ◽  
Fuqian Yang
Keyword(s):  
Shape Function ◽  
Complex Anion ◽  
Practical Importance ◽  
Synthesis Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Accordance ◽  
Low Dimensional ◽  
Low Dimensional Materials

Determining the degree of preferred growth of low-dimensional materials is of practical importance for the improvement of the synthesis methods and applications of low-dimensional materials. In this work, three different methods are used to analyze the degree of preferred growth of the Ni(OH)2 nanoplates synthesized without the use of a complex anion. The results suggest that the preferred growth degree of the Ni(OH)2 nanoplates calculated by the March parameter and the expression given by Zolotoyabko, which are based on the analysis and texture refinement of the X-ray diffraction pattern, are in good accordance with the results measured by SEM and TEM imaging. The method using the shape function of crystallites is not suitable for the determination of the preferred growth degree of the Ni(OH)2 nanoplates. The method using the March parameter and the expression given by Zolotoyabko can be extended to the analysis of block materials.

scholarly journals What did Erwin mean? The physics of information from the materials genomics of aperiodic crystals and water to molecular information catalysts and life

2016 ◽  
Vol 374 (2063) ◽  
pp. 20150067 ◽  
Author(s):  
D. P. Varn ◽  
J. P. Crutchfield
Keyword(s):  
Materials Science ◽  
Second Law Of Thermodynamics ◽  
Information Theoretic ◽  
Information Measures ◽  
New Class ◽  
Erwin Schrödinger ◽  
Low Dimensional ◽  
Aperiodic Crystals ◽  
Low Dimensional Materials ◽  
Compare And Contrast

Erwin Schrödinger famously and presciently ascribed the vehicle transmitting the hereditary information underlying life to an ‘aperiodic crystal’. We compare and contrast this, only later discovered to be stored in the linear biomolecule DNA, with the information-bearing, layered quasi-one-dimensional materials investigated by the emerging field of chaotic crystallography . Despite differences in functionality, the same information measures capture structure and novelty in both, suggesting an intimate coherence between the information character of biotic and abiotic matter—a broadly applicable physics of information. We review layered solids and consider three examples of how information- and computation-theoretic techniques are being applied to understand their structure. In particular, (i) we review recent efforts to apply new kinds of information measures to quantify disordered crystals; (ii) we discuss the structure of ice I in information-theoretic terms; and (iii) we recount recent investigations into the structure of tris(bicyclo[2.1.1]hexeno)benzene, showing how an information-theoretic analysis yields additional insight into its structure. We then illustrate a new Second Law of Thermodynamics that describes information processing in active low-dimensional materials, reviewing Maxwell's Demon and a new class of molecular devices that act as information catalysts. Lastly, we conclude by speculating on how these ideas from informational materials science may impact biology.

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