The study of how the properties of matter arise from its structure at all scales and of how processing can be used to modify those properties (often in pursuit of a specific application).

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2
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2answers
619 views

Penetration of human skin [closed]

I recently found an answer for the "toughness" of steel http://physics.stackexchange.com/a/16821 and was hoping to get a similar answer regarding human flesh. How much pressure is required to ...
0
votes
0answers
17 views

How to make glass surfaces with different hydrophobicity level?

I have a number of small glass beads (d= 2.0 mm) and I need to use a method to make the glass surface hydrophobic. How can I create glass beads with different wettability levels (i.e. various contact ...
0
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0answers
107 views

Formulae for Elastic Hysteresis of rubber

Being a school student, I'm pretty sure we don't need to explicitly learn any formulae helping us evaluate the energy dissipated by mechanical internal energy in a hysteresis loop. But I was wondering ...
1
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0answers
37 views

Twin and Detwin Crystals [closed]

Hello i would like to ask , what are twin and detwin monocrystals? what has to do with their crystalographic symmetry? any consequences ? any image also would be really helpfull! Thank you
1
vote
1answer
109 views

Why does the bulk modulus of water have a maximum at around 60-70ºC

So I'm doing some water hammer analysis and was calculating bulk modulus of water as a function of temperature. I took the speed of sound and density of water as functions of temperature and ...
3
votes
0answers
23 views

How does flow rate affect plume dynamics and film properties in PLD?

So I use a home-built Pulsed Laser Deposition(PLD) system to deposit metal oxide thin films. I use a $ 248\ \mathrm{nm KrF}$ laser. I recently deposited two films under slightly different conditions. ...
1
vote
1answer
90 views

Properties of “hard light”

According to this, and this, we now have the ability to make "light molecules", which, from my admittedly layman understanding, have something to do with rubidium atoms, vacuum, and temperatures near ...
4
votes
1answer
155 views

Why do neutron stars have solid crusts?

A long time ago I read that neutron stars have a solid crusts that are several orders of magnitude harder/stronger than alloys here on the Earth. So how is this possible ? A neutron star has a ...
1
vote
1answer
45 views

Process of x-ray crystallography

This is a pretty basic question but I would just like some confirmation of what I suspect is true. As I understand it, the basic idea behind x-ray crystallography is that we take our crystal and hit ...
0
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2answers
44 views

Electricity from something other than a solid

Is piezoelectricity only limited to solids or can liquids or non-Newtonian fluids create a current when compressed?
-2
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1answer
241 views

Is there any metal or any material that can survive the Sun? [closed]

If we were to send a unmanned spaceship through the Sun. What material can survive?
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3answers
201 views

How to cut graphene?

How is graphene cut, given that it is similar in strength and hardness to diamond? I assume you cannot just take a pair of regular scissors to a sheet of it and cut out the shape you want?
2
votes
1answer
229 views

What is the significance of the Debye temperature from a materials perspctive?

If I look at a table of different metals and their Debye temperatures, what does the variation in these temperatures tell me about these materials?
0
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1answer
41 views

Nomenclature “Material System”

This is just a quick question about nomenclature from General Relativity. Most textbooks refer to "material systems"; 1) Does a material system have to be a system with mass? or can it just be a ...
0
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0answers
24 views

Search strategies in Material Science

Material scientists often search for new materials with engineered properties. If, for example, you have a set of doped semiconducting materials with different doping levels, and you aim for maximal ...
3
votes
0answers
115 views

What does a sheet of graphene look like?

What does a sheet of graphene look like? At one atom thick, is it visible to the naked eye? Can it be handled (by hand) with being torn? Can it be felt at all? [Assuming a large enough sheet ...
0
votes
1answer
976 views

Why are HCP materials brittle whie FCC materials are ductile?

Why are hexagonal close packed materials brittle, While face centered cubic is ductile. Is it related to crystal planes?
0
votes
1answer
28 views

Constant pressure, constant wall thickness, expanding volume = explosion?

Just been idly thinking about a gas cylinder I sometimes use. Pressure is about 200 Bar, or roughly 20 MPa. If I kept the same thickness of steel wall, and the same pressure, but made cylinders bigger ...
0
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0answers
33 views

is full spectrum transparency possible?

Are there materials fully transparent throughout the spectrum? (transparent to all frequencies). And if there's no such substance exists, is it even physically possible to design/make one?
2
votes
1answer
128 views

Heat Expansion of an Aluminium Ring with hole

I have a question of how aluminium will behave when heated ( I made a drawing below to explain the question) We have a ring of aluminium and a hole (green in drawing), if we heat the ring it will ...
0
votes
3answers
95 views

Is it possible to build planet-sized non-spherical structures?

Beyond certain size and density the celestial objects tend to admit a spherical size. I wonder if is there a fundamental mass, density or specific strength related number which when surpassed a non-...
2
votes
2answers
127 views

Why doesn't dielectric materials have coloured reflections like conductors?

I'm a 3D artist trying to learn the basic (or perhaps even intermediate) level of physics of photorealistic rendering. But most artist and tutorials on the internet have little to no clue of the ...
0
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0answers
24 views

Temperature bending stiffness of FR-4

I'm designing a PCB with metal over touch buttons. I have a colleague who want's to test the device reliability by building a tester that using pneumatic cylinders will test all the buttons. He's main ...
0
votes
2answers
82 views

How tall is the tallest Jell-O structure possible?

Given Jell-O with a particular consistency, how tall a structure could be built out of it before it collapses?
0
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0answers
38 views

Can measurement of Spontaneous Magnetization and susceptibility lead one to deduce the magnetic structure of a magnetic compound?

For a given magnetic compound, spontaneous magnetization and susceptibility are measured at various temperatures (in this paper). (SMS measurement) From neutron diffraction data the compound is found ...
0
votes
1answer
55 views

Might a diamond with impurities (doped) be less brittle than a pure diamond?

Diamonds are extremely hard (resistant to pressure) but quite brittle (susceptible to shock). Sufficient impurity will compromise hardness, but I am finding it difficult to find out the effect on ...
1
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0answers
23 views

Why aren't most ionic/covalent/metallic materials self-healing?

For the most part, only soft-matter materials appear to possess self-healing capabilities (that is, if I cleave the material and then press the two halves together, the material re-forms) at room ...
0
votes
1answer
61 views

Is hysteresis essential for a memory system or material?

I want to know whether its essential for a memory system or material to have hysteresis between two of its variable ? If Yes, what can be the general relation of volatility of a memory with its ...
2
votes
1answer
56 views

Why is GaN better than Si as a substrate for ZnO thin film?

in an attempt to grow a thin film using ZnO, I found many researches use silicon as a substrate and others use GaN. by further research I found that GaN is preferred than silicon but I don't know the ...
13
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1answer
178 views

Synthesis of Fe-based superconductors

Polycrystal cuprate superconductors are generally prepared by solid state reactions: Starting reagents are in powder form, they are mixed to each other and placed into furnace on high temperature (...
0
votes
1answer
75 views

Why does the stiffness of organic polymers (plastic) change so much with small changes in temperature?

This is on the borderline between Physics and Chemistry, but I would like a Physics perspective. I am guessing that plastics are a glass-like phase, rather than a true solid.
1
vote
1answer
40 views

Why is metal stiffer at lower temperatures?

Each morning I cycle to school and lock my bike with a thick steel wire (about 8 mm thick). I noticed that it's much harder to change the shape of the wire in the morning when it's much colder than ...
1
vote
3answers
277 views

Any scientific basis behind “crystal energy”? [closed]

I always hear people talking very loosely about the terms "vibration" and "energy" in relation to crystals. Is there any scientific basis in "crystal energy" or is it purely metaphysical ...
2
votes
2answers
373 views

Why is tearing paper irreversible?

Consider a piece of paper. If I pull on it in the right way it tears into two pieces. However, if I push those two pieces together, they do not spontaneously form a single piece. What happens at the ...
-4
votes
1answer
89 views

Flattest possible surface? [closed]

a) What is the flattest surface possible of any material? b) What is the flattest surface material available to humans at the present time?
0
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3answers
96 views

Physical properties of niobium pentoxide ($\mathrm{Nb}_2\mathrm{O}_5$) for thermal simulation

I am looking all day long for heat capacity, thermal conduction, and expansion coefficient of niobium-pentoxide. I want to conduct a thermal (heat flow) analysis on this and need it as input data. Can ...
2
votes
2answers
60 views

Quenching of binary alloy: Concentration equilibrium

I'm currently reading "Models for phase separation and their mathematics" by Paul C. Fife and there is a paragraph which I don't understand because I lack the necessary background in physics/...
2
votes
1answer
127 views

How to make electrical connection to silicon wafer for testing?

I am trying to make an electrical connection to a silicon wafer using a wire (approx 32AWG). I find that conventional lead/tin (60/40, no flux) solder cannot adhere well to the silicon wafer, since ...
0
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0answers
34 views

Equilibrium and constitutive relation

The constitutive stress-strain relation, say $\sigma=Y\epsilon$ where $Y$ is the Young's modulus, gives you stresses. At equilibrium, force balancing (say, with respect to a internal pressure $p$) ...
0
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0answers
31 views

Stress profile of pressurized bent shell

Consider a pressurized cylindrical shell of radius $r$ and pressure $p$, which at equilibrium has a nonvanishing in-plane stress components $pr/2$ and $pr$. This result is generically found by force-...
0
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0answers
40 views

Mooney-Rivlin coefficients sign

I'm doing a fitting of uniaxial compression data of a isotropic polymer using the Mooney-Rivlin model: $\sigma=\left( 2C_1 + \frac{2C_2}{\lambda} \right )\left( \lambda ^2- \frac{1}{\lambda } \right)$...
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0answers
28 views

Lower Threshold optical beam limiter?

We would like to implement a very fast beam limiting, so far google search shows that the common threshold ranges is in 1J/cm^2 or more, this could take seconds to activate as our laser ranges from 1 ...
4
votes
2answers
279 views

Is it possible for an object to have low specific heat capacity and low thermal conductivity?

As I see, there are many examples of object with low specific heat capacity and high thermal conductivity and vice versa. Since they are different properties of matter and their definitions are not ...
0
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2answers
629 views

Does the thickness of a rubber sheet affect the tensile strength?

I'm really confused which thickness of rubber sheet I should choose. Does the thickness affect the tensile strength and elongation in any way? Is there any relationship between them?
11
votes
1answer
600 views

Why does plastic turn white in the area of stress?

There is a phenomenon with plastic in which it changes color to white in areas where stress is applied. When I bend a plastic rod the area in the centre, it turns white or loses colour. Why does this ...
-7
votes
2answers
4k views

Can jet fuel melt steel beams? [closed]

Common sense suggests that steel beams should not yield under burning jet fuel without presence of other substances that produce very high temperatures when burning, such as thermite. So can jet fuel ...
0
votes
0answers
21 views

Flamant's use of mass and weight

I apologize for the stupid question, but I've consulted teachers and found their answers unsatisfactory. Professor E.Brune, in the XIX century, delivered a course on l'École des beaux-arts on ...
0
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0answers
13 views

Role of Mn in Perovskites

Good Day everyone!i don't if its the right site to ask this, but by the way, right now i'm searching for possible research in magnetoresistance properties of perovskite. So far, i already know the ...
4
votes
1answer
135 views

Why can gold be drawn out finer than light?

The metal gold is extremely malleable. Gold is also ductile and one ounce can be drawn into 80 km (50 miles) of thin gold wire (5 microns diameter) to make electrical contacts and bonding wire. I ...
2
votes
1answer
64 views

Does Hooke's Law apply for microscopic amounts of compression?

I would like to set up a simple laser interferometer to measure the compression of a material experiencing forces around $8 \times 10^{-4}$ N. But I need to find the spring constant to calculate the ...