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.
311
questions
2
votes
0answers
29 views
Why do silver halide crystals in suspension, develop a surface charge
This is a question related to analog photography. Photographic films have a suspension of silver halide crystals in them, and these crystals have adsorptive properties which are used in this ...
6
votes
2answers
375 views
For a given packing (hcp, fcc, bcc), which ions occupy the corners and which occupy the faces or centers?
I recently came across the packing of atoms in unit cells. I wanted to know if there was a way to tell where the atoms in the unit cell are just by knowing the compound and its packing (hcp, fcc, etc.)...
3
votes
0answers
50 views
Is dehydration of cobalt(II) chloride hexahydrate dynamic equilibrium?
I know that the dehydration of cobalt(II) chloride hexahydrate is a reversible reaction, is it a dynamic equilibrium?
$$
\begin{align}
\ce{CoCl2·6H2O &<=> CoCl2·2H2O + 4 H2O}\tag{R1}\\
\ce{...
0
votes
0answers
73 views
Determine anion radius in FCC cell
The edge length of an FCC cell is $\pu{508 pm}$. If radius of cation is $\pu{110 pm}$, the radius of anion is?
My approach:
$$(2R_{\text{cation}}+2R_{\text{anion}})^2=2a^2$$
Which on simplification ...
0
votes
1answer
74 views
Adsorption on solids - homogeneous/heterogeneous surface definition
How could we define homogeneous and heterogeneous surfaces (rigorously)?
It is among my exam questions (but I could not find any definition in my textbook or on the internet).
I would say the ...
3
votes
1answer
63 views
What is the maximum length of peptide which considered to be hard for synthesis by the current technology?
I am a molecular biologist and work with recombinant proteins. I am wondering what the cut point, in terms of length, is at which I should produce the peptide using heterologous expression rather than ...
-1
votes
1answer
195 views
How many 4th nearest neighbours are there in an hcp lattice?
My teacher told us that there are 18 4th nearest neighbors in an hcp lattice, at a distance of √3a . I have only been able to identify 12.
Can you help me find all the 4th nearest neighbors?
0
votes
0answers
32 views
Why do we have to use octahedral voids for formula making in solid state chemistry?
Allow me to take an example to explain myself.
Q) What is the formula of a compound in which the element Y forms a ccp lattice and an atom of X occupy ${1\over3}$rd of tetrahedral voids?
Now to find ...
6
votes
0answers
75 views
Correct Definition of Absolute Electrode Potential
I thought absolute electrode potential is Galvani potential difference at the interface. However, it is given by following equation in John Bockris - Modern Electrochemistry (Ref.1): $$ E^M \mathrm{(...
2
votes
1answer
88 views
Understanding packing in different dimensions
In one dimension, there is only one way of packing, that is keeping the balls next to each other.
In two dimension, we can keep a line of spheres on top of another line directly or we can keep the ...
1
vote
1answer
439 views
Radius ratio of octahedral interstitial site in BCC lithium
Problem
Determine the minimum radius of an atom that will just fit into (a) the tetrahedral interstitial site in FCC nickel and (b) the octahedral interstitial site in BCC lithium.
Solution
(a) For ...
2
votes
0answers
171 views
Why is Cu2o[Copper(I) oxide] a (p-type)semiconductor?
Statement:
Cu2O[Copper(I) oxide or cuprous oxide] is an extrinsic (p-type) semiconductor.
Main Question:
But why is Cu2O an extrinsic (p-type) semiconductor?
My confusion:
I understand how Silicone ...
1
vote
0answers
30 views
HCP and hexagonal primitive cell [duplicate]
There are 14 types of Bravais lattices one of them is hexagonal which is just present as primitive cell ie the basis are at its corners , now when I read about hexagonal closed packing I came to know ...
7
votes
1answer
57 views
In solid-phase peptide synthesis, why are the formation of aspartimides a problem but not "glutamides"?
I'm studying solid-phase peptide synthesis (SPPS) at the moment, and a common problem is the formation of aspartimides, which disrupt the synthetic process.
I understand how they form and why are they ...
8
votes
2answers
762 views
Why are there exactly 5 types of two-dimensional lattices, and what distinguishes them?
In the book Chemistry: The Central Science, they introduced the following 5 types of two-dimensional lattices:
The book said that the blue square represents the unit cell, the black dots are lattice ...
4
votes
0answers
42 views
Bond formations in doping of semiconductors [duplicate]
I was reading about semiconductors and found out that semiconductors are doped with either 13th group or 15th group elements which are named p-type and n-type semiconductors, respectively. In n-type ...
1
vote
0answers
37 views
High symmetry points and x-coordinates
Is it possible to work out the x-coordinates related to high symmetry points?
The software I'm using doesn't provide me with that, so I was wondering if there is a way to manually figure it out, as I ...
3
votes
1answer
70 views
Cationic vacancies created when non-stoichiometric iron oxide is doped with silicon(IV) ions
Problem
It is believed that non-stoichiometric compound $\ce{F_{0.93}O}$ forms by doping of $\ce{Fe^3+}$ ions in $\ce{FeO}$ crystal by replacement of $\ce{Fe^2+}$. Calculate the number of cationic ...
6
votes
3answers
1k views
Why is sea salt coarse?
What makes sea salt coarser than other salt?
I have tried checking online but no one seems to discuss this. It seems that the grain of sea salt is larger, but I don't understand since the salt is ...
2
votes
0answers
55 views
What makes up the conduction band?
Prologue/Rant about online classes
We have been taught the electron sea model to explain metallic bonding and conduction of electricity by metals. Then out of the blue, the band theory was introduced, ...
0
votes
0answers
77 views
Unit cell of hcp structure
It is given in my book that the structure in figure-1 is the unit cell of hcp structure.
So why then is the structure in figure-2 not the unit cell as we can repeat the structure in figure-2 to get ...
2
votes
1answer
104 views
Why is the disordered CuAu structure more stable at high temperatures?
I know that the disordered CuAu structure is based around FCC whereas the ordered CuAu structure is tetragonal. Why would the FCC structure be more stable at high temperatures?
For context, I was ...
4
votes
1answer
103 views
Getting an “index” of 7 for a set of powder diffraction data
I tried to index powder diffractogram from the following problem:
A metal (of density $\pu{0.862 g cm^-3})$ gives the following powder X-ray diffraction data $(\lambda = \pu{1.5418 Å}).$
$$2\theta \...
-3
votes
2answers
944 views
Coordination number of 3D close packing [closed]
Can anyone explain me that how the coordination number of corner sphere of this 3-D packing is 6 ? it should be 3
0
votes
0answers
32 views
How many types of 3D packing are possible?
In my book it's said that there are 3 types of unit cubic cell - primitive , face and body centered . But for 3d packing types they have only mentioned FCC and HCP . I know that these 2 concepts- ...
2
votes
1answer
128 views
On the exact definitions of Frenkel and Schottky defects
The wiki page on vacancy defects says;
It is also known as a Schottky defect, although in ionic crystals the concepts are not identical.
As far as I'm aware, they're the same. Furthermore, the wiki ...
1
vote
0answers
55 views
Pressure vs electric conductivity in solids
If we apply pressure to a solid, does it change its electric conductivity? I am asking this because in 2020 they announced a superconductor at room temperature but under a pressure of 3/4 of the ...
0
votes
1answer
132 views
Height of CCP Lattice
Are the height of the Cubic Close packing Lattice and the cubic Hexagonal Close Packing the same?
My understanding says that these unit cells are formed by different arrangement of atoms, ABC for CCP ...
4
votes
0answers
85 views
Why is ruthenium dioxide a conductor while titanium dioxide is an insulator?
Ruthenium dioxide has the same crystal structure as rutile (titanium dioxide), and the metal atoms are in the same oxidation state. Yet ruthenium dioxide is a metal-like conductor (its resistivity is ...
0
votes
0answers
24 views
Degenerate semiconductors /N type dopants/Low fermi level
In extrinsic semiconductors the donor level of some N type dopants is lower in energy than some other dopants . For example as we move from the V to the VIII group if we draw the band diagram the ...
1
vote
1answer
1k views
How is Gibbs free energy related to stability? [closed]
I have been learning thermodynamics for quite some time and I fail to relate Gibbs free energy and stability.
For example, how do I compare stability of metal oxides using the following data?
Also, do ...
0
votes
0answers
46 views
Interatomic spacing vs electric conductivity
I have a theory which may be wrong but I will write it down.If 2 elements at the same group (in solids)have the same crystal structure then the one with the biggest interatomic spacing has better ...
2
votes
2answers
100 views
Clarification of term symbol explanation of laser crystal doping from textbook
I am currently studying the textbook Diode Lasers and Photonic Integrated Circuits, second edition, by Coldren, Corzine, and Mashanovitch. Chapter 1.2 ENERGY LEVELS AND BANDS IN SOLIDS says the ...
2
votes
2answers
584 views
Silicon–Boron Covalent Bond
This is a semiconductor-related question, but in order to understand the acceptor level energy state of boron in bilicon, I figured I'd ask here for hints.
Boron is a p-type material when introduced ...
0
votes
1answer
163 views
Is the lattice point in ZnO crystal structure occupied by the molecule ZnO or the ion O^2-/Zn^2+?
I learnt that ZnO has a hexagonal crystal system. I was expecting that cations or anions would occupy the lattice points in hcp while voids would be occupied by anions or cations respectively. But ...
0
votes
1answer
118 views
What is the form of the Hamiltonian for solids?
For atoms, and even molecules, I can understand how the Hamiltonian would be constructed, but what of solids (as in, for electronic structure calculations)? Thank you for any help.
1
vote
1answer
77 views
Interplanar distance given Miller indice of the planes
Say we've a cubic crystal of unity edge length.
A set of planes in such a crystal is specified by their miller indice as $(3 2 0)$. One of these planes then has intercepts on the axes as $(2 ,3 ,\...
1
vote
0answers
44 views
How to calculate planar density of a face /plane of crystal with cation and anions?
Planar density is given by numer of atoms in plane /plane area .
Suppose I want to calculate
planar density of 100, 101 and 111 planes of Nacl. Radius of Na+ and Cl- ions is 0.086 nm and 0.126 nm.Na+ ...
0
votes
0answers
44 views
Where are the tetrahedral voids and octahedral voids located in an FCC? [duplicate]
A crystal is made up of atoms X, Y, and Z. Atoms X are in FCC packing, Y occupy all octahedral voids and Z occupies all the tetrahedral voids. If all the atoms along two body diagonal are removed, ...
-3
votes
1answer
98 views
Ice geometrical shapes [duplicate]
https://en.wikipedia.org/wiki/Ice
https://www.google.com/search?q=ice&prmd=inmv&sxsrf=ALeKk028fJvrUcWLWu8EV-KsRGuiw0iWWw:1596098668929&source=lnms&tbm=isch&sa=X&ved=...
1
vote
3answers
147 views
Why water cools from outside to inside?
It is a well-known fact that
Water kept in a container, on cooling, results in freezing with initially at the circumference of surface
(1D), then on the surface (2D) and then throughout the volume (...
0
votes
0answers
38 views
"e and a" as combinations of pi bonds
I am trying to get a better intuition on solid-state physics but I am a chemist by degree. I came across this article that attempts to bridge the gap between solid-state physics and molecular ...
5
votes
0answers
111 views
How is the Born-Lande equation modified when the structure is not NaCl?
Often the Born-Lande equation is quoted (alongwith the calculation of the Madelung constant and Born exponent) with reference to rock-salt structure. But what if we take some other crystal, like ...
0
votes
1answer
28 views
Doping of a solid with impurities [closed]
This question is a continuation of the previous question of mine:press me if you wish
And my question is how can I dope a solid with impurities and if the process can be understood with basic ...
0
votes
2answers
236 views
How to identify if a material is perovskite or not?
This is more of a materials science question, but I believe many of you have referred NIST Inorganic Crystal Structure Database (ICSD) database.
I am collecting a database of perovskite materials and ...
0
votes
1answer
370 views
Are HCP and Primitive Hexagonal Unit Cell the same thing? [closed]
In HCP, the [2D] Hexagonal packed layers are arranged in ABAB form. The same happens in Primitive Hexagonal Unit Cell. So does that mean they are the same? If not what differentiates one from the ...
1
vote
2answers
522 views
Why rutile structure have primitive unit cell instead of body centered?
In the literature (Wikipedia), I read that $\ce{MgH2}$ have a structure of rutile. Then, I looked at its space group which is $P4_2/mnm$. From this notation, I understood that it possesses a (...
0
votes
0answers
41 views
Do all metals expand on heating? [duplicate]
This question came up when I was reading about substances with negative thermal expansion. The article by Takenaka [1] gives a good list of materials displaying negative thermal expansion. I noticed ...
0
votes
0answers
60 views
How can fluorite structure exist?
From the information from Google the radius of $\ce{Ca^2+}$ cation is $100 \,\pu{pm}$ and of $\ce{F-}$ anion is $132\, \pu{pm}$, so essentially $\ce{F-}$ ion should form the Bravais lattice (FCC/CCP) ...
-3
votes
2answers
199 views
Change in the number of ions due to exchanging ions [closed]
If the position of Na+ and Cl- are interchanged in NaCl having FCC arrangement of Cl- ions then what change we can observe in the unit cell of NaCl.
I am confused as how the contribution will change ...
