Study of chemical species that are in solid phase, either in cases of their properties, or about ways of synthesizing them.

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Voids vs Interstitial Site?

I am studying solids states. So we studied different lattices of Ionic solids by introducting smaller Cations into VOIDS. Next topic is of defects. SO it is written Frankel defect arises when a ...
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50 views

19F MAS NMR chemical shift tensor and the crystal structure

$\ce{^{19}F}$ MAS NMR is measured on fluorine-doped $\ce{TiO2}$. $\ce{F}$ is to substitute $\ce{O}$ and the crystal structure is anatase, which has a tetragonal crystal system with a space group ...
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16 views

Calculating entropy change when heating a solid [closed]

I got a question on a test, as such : Assume we have 1 mole of a solid, all units in J. Also assume ideal crystal solid has 0 entropy at 0K. Suppose the absolute entropy of a solid at 100K is 20J. ...
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70 views

Why are certain reflections forbidden in body centered cubic and face centered cubic structures?

I know that for body centered cubic structures the allowed reflections only happen if h+k+l is even and reflections are forbidden is h+k+l is odd, and for basic face centered cubic structures ...
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Electronic Transport Phenomena not covered by Bandstructure in Solid State Physics

From what I have read, most of the electronic transport phenomena in solids state physics seems to able to be determined with the bandstructure. Schottky Barriers, bandgaps, band discontinuities can ...
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25 views

Fraction of cube Volume empty [closed]

The unit cell in a body centered cubic lattice is given. Each sphere has a radius r and the cube has a side a. What fraction of the total cube volume is empty?
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21 views

Band alignment of heterojunctions

I have seen several band bending diagrams in journals and the web. However, I am not sure as to how they align them. Some diagram appear to align the vacuum level and some align them by Fermi Level. I ...
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25 views

Zinc oxide reduction in ethanol

I'm trying to prepare a ZnO thin film deposited on a glass substrate. The precursor solution prepared by sol gel process through dissolving 1 M zinc acetate dehydrate (ZAH) in ethanol with ...
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317 views

Why are X-rays used in crystallography?

Can any other wavelength of electromagnetic radiation be used? Why can't gamma radiation be used?
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206 views

Materials with solid volume greater than liquid volume

Water has a solid volume greater than its liquid volume. This question is in two parts. 1) Are there other materials that have solid volumes greater than liquid volumes? 2) What about the structure ...
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149 views

Colour due to F-centre is same as that produced in a flame test, why?

I have noticed that the colours that the F-centres impart in Alkali metal halides are the same that the corresponding alkali metals impart to their flames. $\ce{NaCl}$ when heated in an atmosphere of ...
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36 views

What are the physical properties of exotic ice?

This chart shows the phases of water that form at various combinations of pressures and temperatures. It has multiple exotic forms of ice (labeled II through XV) listed. What are the physical ...
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64 views

How to calculate Madelung's constant for NaCl?

Madelung's constant for $\ce{NaCl}$ is $1.748$. What I tried to so is sum up all the individual interactions into $1$ component where the $X$s are the nucleus and the electron if it was a $2$ atom ...
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37 views

How can the bulky octadecyltriethoxysilane molecule promote single-crystal growth?

Octadecyltriethoxysilane is very bulky (source), yet it was used to promote single crystal growth (source). How can such a bulky molecule induce crystal growth? (For example epitaxial growth ...
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25 views

What is the number of particles in unit cell of diamond? [closed]

Diamond forms fcc lattice and hence should ideally have 4 particles in unit cell. But due to presence of extra atoms it has 8 particles in unit cell.
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43 views

Sulphur in powdered form: what structure?

Quoting this paper: A variety of allotropic states of elementary sulfur have been identified. Solid crystalline sulfur exists either as rings of 6-12 sulfur atoms (cyclohexasulfur, $\ce{S6}$, ...
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How dangerous are non-soluble trivalent thallium compounds?

I am PhD student in solid state physics. I have been working with a fine powder of a transition metal oxide containing trivalent thallium. The oxide is not soluble in water. In my university, ...
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40 views

Tetrahedral arrangement of particles in cubic unit cell

What is arrangement (diagrammatically) of particles (atoms) in cubic unit cell so that I can correctly find out the radius ratio?
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72 views

Oxidation state of metal ion in unit cell

If a cubic unit cell for a metal nitride has nitride ions at all face and corner positions, and metal ions at all edge positions, what is the oxidation state for the metal ion in the nitride? I ...
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Reference request for properties of amorphous titanium carbide (a-TiC)

I assume through some side reaction I'm getting $\ce{TiC}$ in my $\ce{TiO2}$ samples after calcination and I need some basic information about the properties of amorphous $\ce{TiC}$. Is it ...
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20 views

What is the difference between phase of matter and state of matter? [duplicate]

I am still confused on the differences between the phase of matter and state of matter
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1answer
72 views

Why some compounds form different crystal structure at different temperature?

Lets take an example :- Sodium superoxide has three different crystal structure, the marcasite structure at nearby 81 K, the pyrite structure between 196 K and 223 K and calcium carbide ...
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1answer
70 views

Relationship between coordination numbers and stoichiometry

In fluorite ($\ce{CaF2}$), the coordination number of $\ce{Ca}$ is $8$, and that of $\ce{F}$ is $4$. Is there any logic behind the ratio of coordination numbers being the same as the stoichiometry of ...
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1answer
168 views

What is the lattice structure of manganese?

A transition element is defined as the one which has incompletely filled d orbital in its ground state or in any one of its oxidation state. Zinc , cadmium and mercury are not typical transition ...
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1answer
52 views

Refractive properties of materials?

I've just read this article about meta-materials with 0-refractive index, which potentially may "permit" light with super-luminous rate /under rate is meant the propagation of light's phase, which ...
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1answer
30 views

How to eliminate electrostatic charges from $\ce{TiO2}$ powder

I have synthesized $\ce{TiO2}$ nanoparticles via sol-gel method and I need to calcine it at elevated temperatures for the crystal phases formation. The powder is very highly charged and not only ...
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36 views

Reason for isotropy in amorphous substances

I'd be thankful if someone explains why amorphous substances are said to be isotropic and crystalline substances anisotropic
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1answer
53 views

Must compounds formed between solids be a solid as well?

My teacher gave us a long list of compounds and asked whether they are solid/liquid/gas at room temp and normal atmospheric pressure. I only know the more common ones (eg. carbon dioxide, ammonia) and ...
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Resource recommendation to visualize voids in hexagonal unit cell

I started learning solid state chemistry recently. I am having great problem visualizing voids in hexagonal unit cell. Is there any online 3D model/drawing which can help me in visualizing? I need to ...
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98 views

How can diamond have a fixed refractive index?

I was doing a lesson on solid states. There were given two kinds of solids namely amorphous solids and crystalline solids. Some differences between these two solids were given in my book. One of the ...
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1answer
183 views

What is the oxidation mechanism of gunpowder?

I've been recently looking into fireworks and the chemistry of explosives, and I found out that, amongst others, one of the most important reactions in gunpowder ignition is the oxidation of charcoal ...
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1answer
93 views

Why is Cubic closed packing called “cubic”?

How is Cubic Closed Packing "cubic" and also how is hexagonal closed packing "hexagonal" ? I have been thinking over this since a few hours but I am unable to visualise. I understand that when ...
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889 views

Why are there only 7 types of unit cells and 14 types of Bravais lattices?

Why are there only 7 types of unit cells and 14 types of Bravais lattices? I was reading about solid state chemistry for the first time and this limitation made no sense to me. I tried to do the ...
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148 views

Why does the dielectric constant of a solid increase due to a Frenkel defect?

In crystalline solids, an atom may be displaced from its original position in order to create a vacancy in the original location. This is referred to as a Frenkel defect. Why does this defect result ...
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386 views

Yellow Color of NaCl

My book says - "NaCl shows metal excess defect, which results into the formation of an F-center in the crystal. This F-center is responsible for the yellow color of NaCl." My question is, how does an ...
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Why is solid phase peptide synthesis limited to 70 amino acids?

I'm reading document about Solid phase protein synthesis (SPPS) from Wikipedia, and according to the document: SPPS is limited by yields, and typically peptides and proteins in the range of 70 ...
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93 views

Stability of radium oxide

Why is radium oxide yet to be isolated when a wide range of other radium (II) compounds are known ?
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112 views

Why is the electrical conductivity of Cu(I) better than that of magnesium? [closed]

My professor said it is because each atom has a different electron and atomic nucleus structure, so bond distance changes. But in some cases orbitals overlap which causes the band gap to disappear. My ...
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1answer
359 views

What is the world's finest powder substance?

What is the world's finest powder substance that has the smallest granules but remains solid?
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123 views

Are molecular optimizations in quantum chemistry really in vacuum?

I know that Gaussian (or other quantum chemical packages) assumes the molecule is alone in vacuum, that is, the molecule doesn't interact with anything, when optimizing the molecule. But I've found ...
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39 views

Interstitial sites: edge and face sharing?

In close packed structures there is one octahedral hole per close packed atom. In a HCP unit cell these octahedra form a chain of face sharing polyhedra. Is this this universal in close packing or ...
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1k views

How does chromium help stainless steel prevent rusting?

Various sources (such as this one) say that stainless steel is stainless because a passivation layer of an oxide is formed, but I haven't found details on why chromium helps create this passivation ...
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37 views

Why so differance in alkali halide's crystal forms?

I always wonder that though Both $\ce{NaCl}$ and $\ce{CsCl}$ are alkali halides, why they adopt different crystal forms, FCC and BCC respectively? and I have a doubt about $\ce{CsCl}$ structure that ...
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34 views

Is hydrolytic polymerisation the mechanism by which the precipitate forms from the neutral complex?

From basic coordination chemistry and acid-base equilibria we understand that a metal hexa-aqua ion can be deprotonated until it's positive charge is balanced by the negative charge of the hydroxides ...
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1answer
905 views

Distance between successive tetrahedral voids in FCC

What is the distance between successive tetrahedral voids in a FCC Crystal structure? The distance between a face centered atom and a tetrahedral void is $\sqrt{\frac{3a}{4}}$ if the cube's edge ...
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463 views

Is there a way to turn alcohol into a solid gel?

I'm wondering if there is a way to turn alcohol or another bacteria killing substance into a solid gel form, sort of like the gel you can use to clean a keyboard. Source: Aliexpress.com Computer ...
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1answer
57 views

Coloration of substances because of F-Centers

In case of metal deficient defects in the crystal lattice of a metal, the positive voids are filled by electrons. How does this result in the coloration of a substance? Does this condition arise ...
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1answer
194 views

Unit cell of CdCl2

I understand that $\ce{CdCl2}$ has a rhombohedral unit cell as shown in this book. However I often find it being referred to as a "CCP analogue" of $\ce{CdI2}$. Presumably it is the chlorides which ...
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1answer
904 views

Are all lattices Bravais lattices?

Can all lattices be described as one of the fourteen Bravais lattices? Is the hexagonal close packed structure also one of the fourteen Bravais lattices?
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What makes ceramic coated pans fail? Is it reversible? [closed]

If one reads reviews on ceramic glazed cookware (esp. frying pans) one pattern becomes apparent: the pan is awesome at first, nothing sticks to it, even with little to no oil. Then, after a few months ...