Questions tagged [metals]
The metals tag has no usage guidance.
433
questions
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24 views
A confusing problem about the Hall effect
I was given the following problem as a part of my assignment/homework:
The electrons in conductors have a Fermi distribution. If a current flows in a conductor, this distribution function is shifted ...
2
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0answers
23 views
Small-parameter expansion in a scattering theory of resistive charge transport in metals
In metals the equilibrium configuration of the electrons is a Fermi
sea of occupied states centered symmetrically about wave vector $k =
0$. In a simple Drude-like transport theory, a small electric ...
0
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0answers
6 views
Isothermal Gruneisen parameter for Germanium?
If phonon density of states peak shifts are purely quasiharmonic, we have $\omega$(V(T)).
If phonon density of states peak shifts shifts are purely anharmonic, we have $\omega$(T).
Does anyone know if ...
9
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4answers
622 views
How is light emitted by an incandescent lamp
I am looking for better understanding of how light is produced in an incadescent lamp. More specifically: how is the kinetic energy of electrons converted to light?
Are we dealing with interband ...
0
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1answer
20 views
Is thermal conductivity in a thin, malleable metal possible or practical without conducting electricity? [closed]
I'm looking to be able to apply and control heat to a malleable metal, ideally a wire. Perfect conditions would be a wire that takes a controlled amount of heat (heated to) between 250-450 degrees, ...
1
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2answers
50 views
If we free a metal plate of free electrons will it become weaker to external mechanic forces?
If we free a metal plate of free electrons by means of a strong electric field will it become then weaker in case of applied external forces? To make it simpler, do free electrons have any role in ...
3
votes
1answer
70 views
Why is lead soft?
As most of us know, lead, at room temperature, is quite soft. You can easily bend a lead rod. You can easily scrape a small piece off it with your nail, and you can even pull a thin long piece apart. ...
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0answers
11 views
Making a structure attached to a pole taller - will it introduce more force on the pole?
I was really trying to find a suitable title for this post, and I understand it might not be suitable for this StackExchange. However, some physics involving bending and forces do come in play, so I'...
2
votes
1answer
35 views
Do metals generally have larger values of Young's modulus than alloys? If yes, then is steel an exception?
In my physics textbook, they have written that metals in general have a higher Young's modulus when compared to alloys.
On the contrary, in the same chapter they have mentioned that steel has a higher ...
0
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0answers
13 views
Graphene tight-binding vs exact band diagram
In undergraduate courses, we study the tight-binding hamiltonian for graphene, assuming only 2pz orbitals overlap. Based on this model, we get the dirac cones, where at the tip graphene behaves like ...
0
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0answers
23 views
Can we distinguish semiconductors, metals and Insulators from Kronig-Penney model?
Can we distinguish semiconductors, metals and Insulators from Kronig-Penney model? Is it only for metals? If we draw the E vs K diagram using the kronig-penney model why energy bands are increasing as ...
101
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11answers
12k views
If I pull a metal bar for long enough with a constant small force, will it eventually break?
Let's say I have a strong metal bar. I pull it apart with a very small constant force -- obviously it doesn't break. However, this would disturb the internal configuration. If I let go, then ...
2
votes
1answer
26 views
Can hot liquid metal be magnetically entrapped?
Is it physically possible that a magnetic field be produced or exist; to contain hot, possibly electrically charged, liquid metal, from one side of the liquid metal, into a shape, at zero gravity, ...
0
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1answer
17 views
Using diverging electric properties for material separation
Considering that metals and dielectrics have different behaviours when exposed to an electric field, is there a method that can separate these two materials from a mixture, as per an example, a powder ...
1
vote
0answers
10 views
Variables in Photoionization and Work Function of metals
Do metals engaged in coordination bond have the same work function and/or photoionization of the pure metal? The outer electron shell still remains the same.
If photoionization were to happen, what ...
0
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2answers
32 views
Definition of metallic state
What is the physical and chemical definition of a metallic state?
I found this term in various books and, although the idea is intuitively clear to me, I would prefer to have a precise and complete, ...
0
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1answer
49 views
What is the thinnest metallic sheet commercially available and what is the thinnest sheet of metal producable in lab?
I was curious reading about rutherfords alpha scattering experiment in which they used the thinnest gold foil available at the time. I was wondering after a 100years how thin the sheet of a metallic ...
4
votes
1answer
73 views
What is the bump in the resistivity vs temperature curve of the nichrome 80 wire?
I have measured the resistivity of a nichrome ($80$ Nickel $20$ Chrome) wire as a function of temperature.
Because my setup is quite crude (just a power supply and a couple of multimeters to measure ...
1
vote
2answers
49 views
Total number of orbitals inside a sphere in $k$ space
In kittel's book on solid state physics it says that for the volume element $(2\pi/L)^3$ there is one distinct triplet of quantum numbers $k_x,k_y,k_z$. Thus in the sphere of volume $4\pi k_F^3/3$ ...
5
votes
2answers
206 views
Does the semiclassical model contradict statistical mechanics?
In the discussion of electrons in metals, often the semiclassical model is used. There, the electrons are treated as occupying localized wave packets $|k,x\rangle$ which have momentum k and position x ...
2
votes
1answer
25 views
Field positive ion emission
A metal is approximately a sea of mobile electrons and a lattice of positive ions. In a vacuum, a piece of metal with enough negative charge will release electrons. Sharp points enhance this effect.
...
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0answers
36 views
What happens to the Fermi level of a metal when a dc electric field is applied?
For metals, the Fermi level $E_F$, which is also equal to the chemical potential $\mu$ at absolute zero of temperature, is the highest occupied energy level at $T=0$. In terms of the electron number ...
0
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1answer
76 views
How dangerous is this arcing wall heater in terms of nanoparticles / metal vapors? [closed]
This question is a follow-on to my previous question, but now more focused and with pictures.
As described in the previous question, the heater sometimes made a hissing noise (imagine white noise, ...
0
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1answer
57 views
Could a Cadet heater release metallic dust into the air?
A Cadet style wall is periodically making a hissing sound. While it makes this sound, I notice my computer mouse is non-responsive. What is the most likely cause of the hissing sound, and how ...
2
votes
2answers
127 views
Electron heat capacity vs phonon heat capacity
For metals, the heat capacity has two contributions. The phonon contribution is proportional to $T^3$, while the electron contribution is proportional to $T$, as $T$ goes to zero. Therefore, for ...
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0answers
19 views
Why is pyrrhotite LESS magnetic the MORE iron it contains?
Usually, the more iron the better....
Pyrrhotite is an iron sulfide mineral with the formula Fe(1-x)S (x = 0 to 0.2). It is a nonstoichiometric variant of FeS, the mineral known as troilite. ...
0
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0answers
15 views
How to ease/reduce surface roughness caused by ion sputtering?
I want to investigate the electron emission of samples under electron bombardment.
Experts will know that surface condition plays a huge role in the emission rate and some other properties (e.g. max ...
0
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0answers
19 views
Charge carrier density for alloys
If we go to Aschcroft&Mermin we find formula for charge carrier density:
$n=\frac{N_AZ\rho_m}{m_a}$
This formula is pretty simple and written in every solid state physics textbook.
So my question ...
0
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0answers
14 views
Consequences of fusing metallic glasses
I have come across some information about metallic glasses which has brought up questions. I have read that due to the need for high cooling rates generally, quantities of metallic glass are only ...
0
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0answers
12 views
Resources for materials science (inconel/alloys)
I am doing a project on the physics of the spaceX raptor engine. I believe it is made out of a certain type of inconel alloy. I want to understand why this alloy has the properties that it does, but I ...
2
votes
1answer
50 views
Why doesnt equipment melt during manufacturing? [closed]
During many manufacturing process, the materials worked need to reach temps above the melting point of many common materials used in equipment.
How is the issue of equipment melting avoided?
Ex, how ...
-1
votes
4answers
398 views
Can we say that iron on heating is a fluid?
When iron is being put on fire, its forces with other atoms starts to break. We know a solid has more atoms and less spaces between them while liquids have more space as compared to solids (Also means ...
0
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1answer
35 views
Can electrons come out due to photoelectric effect from any where else than the surface? [closed]
Can electrons come out due to photoelectric effect from any where else than the surface? Like what can the electrons only from the surface come out.
For a scene,
suppose a light beam of sufficiently ...
0
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0answers
17 views
Ultrasonic waves through metals
Might ultrasonic cleaning process/exposure influence or change the acoustic/resonance of a solid silver or solid gold flute?
Might ultrasonic cleaning process/exposure weaken or damage parts of that ...
0
votes
1answer
27 views
Ferromagnetic field near a ring in Earth's magnetic field
Let's say I am trying to find out the effect that an iron ring has on the Earth's magnetic field (approximated to a uniform field at infinity). Can I solve it in 4 steps:
Find the magnetic field due ...
0
votes
1answer
24 views
How is the main shape of Nitinol made?
I understand that Nitinol is a shape-memory alloy, such that it "reforms to its original shape" when heated to its transformation temperature. But what I don't understand is, how is the ...
0
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0answers
27 views
Why are linear diffusion graphs limited to a max and min value. Graph shown in link
This is the graph
https://prnt.sc/vpwcz6
I have tried various things to understand why the limits are the way they are for the specific metals. I tried to check if the limit is their melting point but ...
0
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1answer
90 views
Why ferroelectric material needs to be insulating?
Is it necessary for a ferroelectric material to be insulating?
Is it possible for a metal to be ferroelectric?
0
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2answers
48 views
Do the ideas of Bloch wavefunction and Bragg scattering of electrons which apply to crystals also apply to liquid Mercury?
Do the ideas of Bloch wavefunction and Bragg scattering of electrons which apply to crystals also apply to liquid Mercury ?
Why is it that electrons in the liquid are not localised by the disordered ...
0
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0answers
47 views
Do metal alloys exist with work function of ~1.4eV?
I am wondering if metal alloys with a work function of between 1.1-1.7eV (ideally 1.4eV) exist?
Some information exists on photoelectric work functions of metals here and here. Cesium seems to have ...
0
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0answers
44 views
Plasma frequencies of metals
The following is in relation to metal plasma.
The dielectric constant according to the Drude-Lorentz model is given by (equation 1):
Furthermore according to the Mark Fox book on Optical properties ...
0
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1answer
30 views
Metallic bonds get weaker during electrostatic induction?
If the cations are held together by the sea of electrons (metallic bonding), and if we apply electrostatic induction then what happens to the region of atoms that have a deficit of electrons? Are ...
0
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0answers
97 views
Dielectric constant or permitivity of copper
I'm trying to simulate a capacitor made of copper plates in comsol multiphysics. What is the value that I should use for the dielectric constant or permittivity of the copper plates? I've read that ...
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2answers
108 views
Why are iron and copper used more than other materials to make cooking pots?
Why are iron and copper used more than other materials to make cooking pots?
3
votes
1answer
56 views
Low temperature resistance of metal
Is there any intuitive explanation of why resistivity of metal goes as $T^5$ at low temperature?
The Debye theory gives that the phonon distribution goes as $n(\omega)\sim T $ at higher temperature ...
1
vote
1answer
41 views
What are the north side and south side magnetic metals called?
What are the two metals that cause the repel force of a north side magnet, and the attract force force of a south side magnet?
0
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1answer
85 views
How do you calculate the theoretical work function of an alloy?
Given a combination of metals or metals combined with one or more other elements, how do you calculate the theoretical work function of the alloy?
3
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1answer
93 views
Materials-science: why anyone telling that high temperature is bad for knifes? (even if this is 45-60 celsius degrees)
As I know tempering of hardened metal must be at temperature close to 150 celsius degrees.
So why exist so widespread idea that you must not use (good) knifes to cut hot products or to wash it in hot ...
0
votes
1answer
29 views
Does metallic bond increase with the increase of atoms?
So, metallic bond doesn't form between two atoms, it forms when there are a large number of atoms.
However, the establishment of metallic bond was statistical, thus there might be a time where ...
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vote
1answer
33 views
Is solar radiation at earth's surface sufficient to eject electrons from aluminum?
Is solar radiation at earth's surface sufficient to eject electrons from aluminum?
