Questions tagged [solid-state-chemistry]

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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In atomic diffusion in Au/Cu metal contact, where do the atoms come from ? (need melting temperature to break bonding in lattice ?)

It is known that Au metal is diffused when it is contacted with copper metal. And Au metal have lattice which consist of atoms. If so, may I think that atom is diassociated from lattice by heating ? ...
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938 views

Please help regarding finding the correct approach {solid states}

In Diamond, carbon atom occupy FCC lattice points as well as alternate tetrahedral voids. If edge length of unit cell is 356 pm then diameter of carbon atom is ________? I got the answer but is it ...
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2k views

Is there an explanation to the atomisation energy trend of transition metals?

I am familiar with the double hump trend for atomisation of transition metals, and I can explain the unusually low atomisation of $\ce{Mn}$ with the exchange principle, specifically that in the solid ...
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1answer
403 views

Schottky Defect in AB2 type crystals

Are there any examples of Schottky defect in ${\ce{AB_2}} $ type crystals. Does Schottky defect require that the cation and anion be of equal size? According to me it is not necessary that the two ...
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933 views

Limiting radius ratio

I recently came across this question while studying Solid State. The coordination no. of [Ni(CN)4]2- is 4 as Ni is bonded to 4 CNs and is planar in structure.Hence its Limiting Radius Ratio must be ...
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How to calculate the height of an hcp lattice?

A hexagonal closed packing (hcp) unit cell has an ABAB type of packing. For calculating the packing fraction we require the volume of the unit cell. Volume of hcp lattice = (Base area) $\cdot$ (...
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55 views

Chemistry of solids: allowed wavevectors

I'm a complete beginner in the chemistry of solids, and many of the things I came across don't make sense. I have two subquestions, which I think it would be most logical to post as a single question. ...
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1answer
55 views

Is it possible to determine the age of a building by just looking at its window?

I've recently come across the fact that glass is an amorphous solid and is known as a pseudo solid or a super cooled liquid. Our teacher told us that buildings that if we were to closely observe the ...
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311 views

Solid state and packing

In NaCl there is a simple cubic unit cell and the coordination number is 6. So i am confused how are both the ions arranged in such a lattice, with such a cordination no as in simple cubic unit cell ...
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467 views

what is meant by stability and potential energy of molecules in cases of formation of bonds?

molecules form chemical bonds in order to gain stability. it is said that forming bonds leads to lower potential energy of molecules and makes them stable. what does stability mean? how formation of ...
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Is Body Centred Cubic arrangement also a kind of packing in solids?

I am confused about the packing thing in solids . I read about Hexagonal Closed packing(HCP) and Cubic closed packing(CCP) then realised this stuff named as Body Centred Cubic(BCC) under the heading ...
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Why color of alkali metal peroxides, superoxides and ozonides deepens down the group?

This is basically a continuation of the question-"Why is potassium monoxide (K2O) coloured?" I knew that color of alkali metal oxides deepens down the group: Lithium oxide ($\ce{Li2O}$) is the ...
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117 views

Synthesis of ZnO by wet chemical method and reducing particle size by ball milling

I synthesized bulk $\ce{ZnO}$ which is pure white in colour, but after high energy ball milling colour changes from white to yellow, why? Figure 1: Zinc oxide (courtesy of Wikipedia).
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226 views

DSC Metal hysteresis (melt/cryst)

So we were analyzing Polymers using DSC and calibrated the system using Indium. I expected it to be a single transition only as Indium only has 1 known crystal structure and as I never worked with DSC ...
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Why is ZnFe2O4 a normal spinel?

Considering that $\ce{Zn^2+}$ is $\mathrm{d}^{10}$, $\ce{Fe^3+}$ is $\mathrm{d^5}$, and $\ce{O^2-}$ is a weak field ligand, the CFSE values of both the normal and inverse spinel structures should be $...
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495 views

Why does crystalline solids have well defined 3d geometry

Crystalline solids have well defined geometry because the intermolecular forces are uniform throughout the solid unlike amorphous solid where it varies from place to place. But still the question ...
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112 views

NiO and ZnO electrical conductivity with oxygen pressure

NiO is a Mott-Hubbard insulator and increasing oxygen concentration leads to anion excess and oxidation of Nickel so electron hopping is more favourable so electron repulsion is reduced and it becomes ...
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1answer
928 views

Why is potassium monoxide (K2O) coloured?

Potassium monoxide is rarely formed and is a pale yellow solid. I don't understand how is this compound coloured because in oxide anion electron cannot excite in the next orbital due to huge energy ...
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243 views

What makes certain zeolites better at ion exchange?

I would have thought that the bigger the pores in the zeolite, the more ions it can contain, and therefore the better the use of the zeolite for ion exchange. However, zeolite A has small pores but ...
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Is glass amorphous solid or supercooled liquid? [duplicate]

I've read that glass is a supercooled liquid. But lately I've came to know in a science info post that glass is amorphous solid. How? Please someone explain me.
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Melting Point of Amorphous Solids [closed]

My textbook says that amorphous solids do not melt at a fixed temperature,but at a range of temperature. It depends on the way the atoms/molecules are present in a given piece of solid. Since the ...
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How are the number of tetrahedral voids twice the number of octahedral voids in a CCP structure?

How are the number of tetrahedral voids twice the number of octahedral voids in a CCP structure? Is there some kind of mathematical proof for it? Is there some way I can understand this intuitively? ...
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Density of Interstitial compounds

I have read in my textbook (not very reliable) that density of interstitial compounds is lesser than parent compound. But how can this be true? We add atoms to the lattice voids, so density should ...
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92 views

Substituting Ulexite

I'm working on ceramic glaze chemistry. One ingredient I don't have, but want to substitute is ulexite: $$\ce{NaCaB5O6(OH)6.5H2O}$$ I have borax, calcium borate, and calcium silicate: $$\ce{NaB4O7 ...
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Surface-dependency of kinetic in speed law?

we can comprehend the quantitative dependency of the kinetic of a chemical reaction through the speed law: $v(t) = k \cdot c(...)^k \cdot c(...)^n$ Here I used the concentration $c$ for that take ...
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What does β stand for in β-potassium zirconate?

What do the Greek letters (α, β, γ...) convey when they are prefixed to a crystalline substance? For example: β-potassium zirconate
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78 views

Is there a substance that is hard (ideally abrasive) in solid form but would dissolve in water?

doing some research for a dishwasher / dish cleaning product and interested in any compounds that could be fashioned into a brush or other abrasive form and then dissolve and wash away with the water ...
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188 views

Band gap of Transition Metal Dichalcogenides

What phenomena is responsible for the shift of the nature of the band gap of transition metal dichalcogenides from being indirect band gaps to direct band gap material once it is slimmed down from ...
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970 views

Reaction speed with solids

It seems that reaction rate is defined as change of concentration over time and the speed doesn’t change if you add more solid. But imagine we have a cube (1 kg) of $\ce{CaCO3}$ that yields 1 mole $\...
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841 views

Is Changing between Allotropic forms a Physical or Chemical Process?

When a substance changes its alloptropic form, is this considered a physical change or a chemical change? Right now, I am thinking that it would depend on what the change was. For example, if ...
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519 views

Distance between two atoms that lie along a body diagonal

It is given that two atoms lie along the body diagonal of a unit cell (crystalline solid). The length of such cubic cell is $a=\mathrm{0.336\,nm}$. My book says that we should take the coordinates of ...
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1answer
5k views

Coordination numbers and radius ratio

According to the image above (source), for a radius-ratio between 0.732 and 1, the coordination number is 8. However, for a radius-ratio of 1, the coordination is 12. This is the same for the boundary ...
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1answer
318 views

Which it is the oxidation state of indium and phosphorus? [closed]

I would like to know what the oxidation state of indium and phosphorus in a structure type rock salt. It could be +1 and -1? Yes or not? and why? Thanks
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What is crystallographic equivalence?

I’ve learnt that in crystallography, there are many crystallographic directions that are “equivalent.” For example, in a cubic crystal system, the [011] and [110] and [101] directions are “...
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1answer
895 views

Calculating the ionic polarizability from the Clausius-Mossoti relation

The concentration of atoms in a crystal is $N_d = \pu{2.24e28 m-3}$, and the relative dielectric constant is $\varepsilon_{r} = 5.62$. The crystal has a refractive index of $n = 1.5$. Using the ...
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2answers
707 views

Cubic crystals anisotropy

My textbook states "Cubic crystals contain four three-fold axes, converting the ellipsoid to a sphere." What indeed is the ellipsoid and sphere in the lattice? I know the meaning of three fold ...
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1answer
425 views

Primitive cells and their variations

Is there any intuitive way(without involving higher maths) to explain possible variations in seven primitive types of (unit)cells? I would like explanation in context of why end centred is possible ...
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260 views

Interstitial Sites in unit cell

I wanted to calculate how many interstitial sites (tetrahedral and octahedral) are present in a simple unit cell and their location and radius. I am guessing they are at the center of unit cell and at ...
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230 views

Solid State - Radius Ratio rules

Why lithium salts crystallize in octahedral lattice , although radius ratio values are much below than expected ratio?
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157 views

Why does the barium ion in barium titanate move in its tetragonal crystal structure?

Barium titanate is known in the materials science world to be a great dielectric. This is known to be because the $\ce{Ba^2+}$ ion sits off center in the middle of the tetragonal crystal structure. ...
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1answer
50 views

Cutting a Solid with a sharp edged tool

The third point of difference suggests that amorphous solids can't be cut into two parts of regular surfaces But glass being an amorphous solid is cut into regular pieces often. What am I getting ...
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127 views

Determine the quantitative composition of a solid sample containing Co, Mn, Al, C, and O

I have a solid sample that contains Co, Mn, Al, C, and O. The sample mass is ~200 mg. I need to determine what the composition of this sample is. I've looked at atomic adsorption spectroscopy, but ...
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63 views

Defects of Crystals

So while studying defects, I found that: Interstitial defect is when constituent particle is present in the interstitial site. My question is where this constituent particle is coming from? As it ...
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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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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 $\ce{...
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615 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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972 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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51 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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921 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 dihydrate $\ce{Zn(CH_3COO)_2.2H_2O}$ in ...
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Why are X-rays used in crystallography?

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