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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Compound metal oxide stoichiometries

When certain oxides are combined in a pre-determined stoichiometry and synthesized with a ceramic-like synthesis process(power-in-tube), multiple phases may be obtained which not necessarily is same ...
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Synthesis of compound metal oxides [closed]

When certain oxides are combined in a pre-determined stoichiometry and synthesized with a ceramic-like synthesis process(power-in-tube), multiple phases may be obtained which not necessarily is same ...
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1answer
41 views

Concentration of electrons in silicon sample with a phosphorus dopant

I'm studying electrical and computer engineering and all I remember from chemistry is from high school. We have a $\ce{Si}$ sample and we want to replace one in every million atoms with a phosphorus ...
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1answer
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Let us say that height of HCP is h then what is the distance of tetrahedral voids [closed]

In a hexaoal cose-packedstructue et $h$ be the spacing between equivalent basal planes. Then what are the "heights" of the tetrahedral voids lying between any two adjacent, equivalent basal planes, ...
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why lattice energy have to be greater than IE and EA? [closed]

Why is lowering effect of the lattice energy not able to be greater than the combined net energy raising effects of the IE &EA?
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1answer
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Calculating nearest neighbor distances

For cubic materials, there are equations in which to calculate nearest neighbor (NN), second nearest neighbor, etc. Can this be done with tetragonal crystal structures? I want to calculate NN, 2NN, ...
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1answer
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Which is the suitable process for ball milling?

Why do we mainly choose the wet ball milling process in spite of dry ball milling process? Both processes are used to make a homogeneous mixture of different compounds.
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1answer
161 views

Thermochromism in PbI2

I noticed while heating some PbI2 powder that it reversibly changes from a yellow to a dark red. However, I was unable to find anything on this thermochromism. There are related cases in TlI and AgI ...
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What is “chemical pressure”?

While reading some publications on solid superconductors, I encountered a term "chemical pressure" a few times, which is usually attributed to the changes of superconducting transition ...
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465 views

To what extent are the radius ratio rules valid for predicting the crystal structure of an ionic compound?

The ionic radii of $\ce{Ba^2+}$ and $\ce{O^2-}$ in barium oxide are $\pu{135pm}$ and $\pu{140pm}$, respectively. The ratio of the radius of $\ce{Ba^2+}$ to $\ce{O^2-}$ is approximately $0.964$. ...
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1answer
675 views

Why we don't talk about unit cells in hcp/fcc structures?

I'm studying basics of Solid State Chemistry from this source. So there are 14 types of Bravais crystal lattices (Primitive + Centered) in 3D. Every solid in this universe is made by the unit cells ...
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35 views

Phases in iron carbon diagram

The definition of phase : Uniform chemical and physical composition. So Alpha iron (0.001% carbon) and alpha iron (0.002% carbon) are two different phases??
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How many tetrahedral and octahedral holes are there in a bcc unit cell?

When I tried to count, I found 24 tetrahedral holes (each formed by 2 body centers of 2 unit cells sharing a face and 2 vertices of the same edge of that face). As each hole is being shared by 2 unit ...
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1answer
203 views

Physical meaning of thermal parameters dimension (Ų)

In single-crystal x-ray crystallography both isotropic and anisotropic displacement parameters $U_{ij}$ of thermal ellipsoids have dimension of square angstrom ($Å^2$) as follows from the definition ...
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How is solid titanium(II) oxide an electrical conductor?

Most salts in the solid state are electrical insulators, since the ions are not mobile (e.g. sodium chloride). However, solid titanium(II) oxide, $\ce{TiO (s)}$, is a conductor. How is this so?
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Can a solid be both crystalline and amorphous? [closed]

The first line in the Wikipedia article for "Glass" reads: Glass is a non-crystalline amorphous solid that is often transparent and has widespread practical, technological, and decorative ...
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Brillouin zones of a compound after structural relaxation

My background in solid-state chemistry isn't much, so I apologize in advance if there arises the need to raise a basic fact while answering my question. I've been learning mostly from the web, with my ...
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How would the crystal structure of sodium stearate look like?

In my lessons of solid state, I was taught about Bravais Lattices, and Face Centered, Body Centered, and Primitive cubic lattices, to name a few. All these crystal structures had this assumption, that ...
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1answer
353 views

Why are p-type solar cells more prone to degradation in space than the n-type ones?

Why are p-type (boron doped substrate) solar cells more prone to degradation in space than n-type (phosphorus doped substrate)? All the sources I've looked at simply state it was found that p-type ...
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Effect of temperature and pressure on structure of solids

What is the effect of these conditions on the structure of solids? My book has the answer that confuses me. I got nothing about it. Can you please explain? The answer of the book is With the ...
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1answer
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What is the definition of porous materials?

Is there a consensus on scientific definition of porous materials? There are many definitions out there which do not seem accurate enough: from wikipedia (accessed July 2017): A porous medium or a ...
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1answer
3k views

Number of atoms per unit cell

I don't understand the concept of unit cell and the number of atoms per unit cell in a cubic lattice also the calculations for the number of atoms. For example in the $\ce{fcc}$ lattice, number of ...
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879 views

What are the effects of frenkel and schottky defects on electrical conductivity of a solid?

How do these two defects impact dielectric constant of solid? Please explain these two questions in detail. In case of frenkel defect the the smaller ions are just dislocated from their initial ...
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What is the reason for isotropy in amorphous solids?

In my book, it's been mentioned that crystalline solids are anisotropic whereas amorphous solids are isotropic in nature. The reason for these has been explained (with a diagram) as: Crystalline ...
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What makes Gorilla Glass more durable with each generation?

Gorilla Glass (GG) is one of the most recognizable brands of toughened glasses today, thanks to their marketing and widespread usage in various gadgets and automobile industry. According to Wikipedia,...
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1answer
175 views

Band structure in half-metals

In a typical band diagram of a half-metal, the band structures for electrons of up and down spin are different. Why is this so?
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Will a solid object lose or gain atoms on standing over time (without being acted upon by external influences)?

Suppose I'm in my room with my keyboard, my desktop and my desk. Are these objects losing or gaining atoms every second? Or are they forever stuck with the same number of particles until you scratch, ...
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What are some materials that expand a lot proportionally to heat?

There's never any source on the internet that can simply give me a list of materials that have the kinds of properties I'm looking for. I'm wondering what materials, like for a solid block of ...
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1answer
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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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986 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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1answer
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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
445 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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1answer
1k 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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1answer
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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
56 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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1answer
316 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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1answer
518 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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1answer
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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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120 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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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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1answer
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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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518 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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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
1k 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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2answers
270 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? ...