# Melting gold at room temperature is a thing now.



## cosmetal (Dec 10, 2018)

From Mining.com:

http://www.mining.com/melting-gold-room-temperature-thing-now/?utm_source=digest-en-mining-181209&utm_medium=email&utm_campaign=digest

*"First, they placed a small piece of gold in an electron microscope. Then they started observing it at the highest level of magnification and began gradually increasing the electric field to extremely high levels. When they reached the highest electric field, they noticed that the surface layers of gold had actually melted – at room temperature."*

I had no idea that they made ceramic crucibles this small! :shock: 

I wonder how they fluxed the crucible? :? 

Those pesky scientists just keep "poking" around with the fabric of our universe. :lol: 

James


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## Palladium (Dec 10, 2018)

Am i missing something here?


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## cosmetal (Dec 11, 2018)

Palladium said:


> Am i missing something here?



_*I had no idea that they made ceramic crucibles this small! :shock: 

I wonder how they fluxed the crucible? :? 

Those pesky scientists just keep "poking" around with the fabric of our universe. :lol:*_ 

All comments made as attempts of jest. 

Especially, the one about scientists "poking" around with the fabric of our universe. After all, that's a big and important part of their job.

Peace,
James


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## macfixer01 (Dec 11, 2018)

This sounds basically a lot like the way that sputtering works, but I guess they would know best if it’s truly something different going on in this process?


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## g_axelsson (Dec 12, 2018)

Those pesky Swedes are at it again, messing with our fine gold.  

In physics melting is a quite well defined process. It's a phase transition between an ordered crystalline state into an unordered liquid state. The force holding a metal together is a sea of electrons so I can see why a high electric field could affect the melting point of a metal... but only at the immediate surface, the electrons would move like a tide inside the metal to counteract any external electrical field so inside the metal there is no net electrical field.

Sputtering on the other hand is the process of knocking off atoms from a target and deposit it on an object by the kinetic action of the positive ions from a plasma. The target surface isn't melted, it's just chipped off in tiny pieces (atom by atom).

Göran


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## rickbb (Dec 12, 2018)

As I understand it, electron microscopy requires the target to be under high vacuum. This would change, (lower), the temperature required to make a phase change in a solid metal. Run enough energy though/at the metal sample and the surface would easily "melt" at room temperature.

In theory you could balance the 3 main variables here, metal source, vacuum level and energy level to melt or vaporize at many different temperatures, even below room temp I suppose.


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## FrugalRefiner (Dec 12, 2018)

Well, Whenever I melt gold it is at room temperature. The gold in my melting dish becomes molten, but the temperature in the rest of the room doesn't change significantly. What they observed is essentially the same. Even under vacuum, gold will not melt at room temperature. The surface they observed had reached a high enough temperature to melt, but because the layer that melted was so thin, the rest of the material did not melt.

Think about soldering or stick welding something. The energy is concentrated at the end of the piece of solder or the welding rod. That bit becomes molten, while the rest of the solder or welding rod remains solid. I see this as the same principal.

Dave


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## Palladium (Dec 12, 2018)

FrugalRefiner said:


> Well, Whenever I melt gold it is at room temperature.
> 
> Dave



I didn't want to make that observation and people to think i was being a smart a**.    
It is a true statement though!

I don't see anything new here besides physics 101.


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## anachronism (Dec 12, 2018)

Palladium said:


> FrugalRefiner said:
> 
> 
> > Well, Whenever I melt gold it is at room temperature.
> ...



Well to be fair the melting point of gold is not room temperature no matter which site you look at or which reference document you choose to reference. Go on someone show me different. Nope you can't so you two can take your shenanigans and semantics and swallow them. :lol: :lol: :lol:


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## g_axelsson (Dec 12, 2018)

The discovery is actually that the surface of the gold had room temperature but still melted under a high electric field. It is not that the room had room temperature. Under normal conditions the melting point of gold is still around 1000 C even if it is under vacuum or at the end of a wire.

What they have done is quite extraordinary and nothing like physics 101.

There are a lot of different ways you can observe gold when it melts. For example with X-ray diffraction you can observe the exact moment when gold goes from an ordered crystal state into a random melted state. I think it would also give an indirect measurement of the temperature from the broadening of the diffraction bands and spots... here is one I prepared before of a gold foil.


(Actually it is an electron diffraction pattern of a gold foil, but the principle is the same as X-ray diffraction)

Göran


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## Palladium (Dec 12, 2018)

I see sarcasm is dead! :lol: :lol: :lol: 
The first part when you think about it is true! What ever room your in is at room temperate of that environment. I melt 2,000 deg gold all the time in a 72 degree room. :lol: 

The part i take reference to i guess on a more serious note is the word melt and room temperature which is in essence click bait. It appears they are doing this on the surface of only a few atoms thick. This is not melting as much as it appears to be Electromigration. Electromigration can occur under intense applied electrical fields and low temperatures just like what they are claiming. They talk of cones like "Taylor cones, which are also a known phenomena in Electromigration. While i will give them kudos for expanding a research field this is far from Noble peace prize territory or some ground break revelation in materials science. Sounds like the run up to the formation of a company and a funding round based on old technology improved and repackaged. Again i'm not knocking any advances, just the hype associated with it.


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## Palladium (Dec 12, 2018)

anachronism said:


> Palladium said:
> 
> 
> > FrugalRefiner said:
> ...



I didn't take you long to jump right in there did it?
Now to show you how stupid that logic you just used sounds the discussion we are having is based on this article that gold DOES melt at room temperature!!!!! So which one is it professor? 

If you can't make that logic make sense then i guess as a wise man once said " take your shenanigans and semantics and swallow them"!

And since you ask for a reference that gold melts at room temperature here is the link to the reference. 
http://www.mining.com/melting-gold-room-temperature-thing-now/?utm_source=digest-en-mining-181209&utm_medium=email&utm_campaign=digest


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## anachronism (Dec 13, 2018)

I'd just refer you to Goran's post. He worded it far better than me however the logic and reasoning remains the same. 

I was trying to be light hearted about it.


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## kurtak (Dec 13, 2018)

g_axelsson said:


> Those pesky Swedes are at it again, messing with our fine gold.



:lol: :lol: :lol: 



> In physics melting is a quite well defined process. It's a phase transition between an ordered crystalline state into an unordered liquid state. The force holding a metal together is a sea of electrons so I can see why a high electric field could affect the melting point of a metal... but only at the immediate surface, the electrons would move like a tide inside the metal to counteract any external electrical field so inside the metal there is no net electrical field.





> There are a lot of different ways you can observe gold when it melts. For example with X-ray diffraction you can observe the exact moment when gold goes from an ordered crystal state into a random melted state.





> Palladium wrote; - It appears they are doing this on the surface of only a few atoms thick.



XRF ?

Kurt


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## kurtak (Dec 14, 2018)

anachronism said:


> Well to be fair the melting point of gold is not room temperature no matter which site you look at or which reference document you choose to reference.



I have to agree with Jon here

The scientists in this article "did NOT" observe gold melting at room temp - at least not at room temp ALONE

Rather - what they observed - was energy being applied to gold & the amount/level of energy needed before gold was observed melting - though the temp of the room - did not change due to the applied energy



> Quote from the article; --- First, they placed a small piece of gold in an electron microscope. Then they started observing it at the highest level of magnification and began gradually increasing the electric field to extremely high levels. When they reached the highest electric field, they noticed that the surface layers of gold had actually melted – at room temperature.



In other words - per the underlined - at the highest level of magnification - they started observing (the gold) --- and (then) began gradually increasing the electric field to extremely high levels --- When they reached the highest electric field, they noticed that the surface layers of gold had actually melted

Granted - during the "experiment" the room temp remained the same - but it was not until the highest electric field was reached that they observed a "surface" melting of the gold


So - they had to "target" the gold with applied energy "before" they observed the surface of the gold melting --- like wise - at that same "room temp" - they also observed - the surface of the gold was NOT molten - until AFTER the highest electric field (energy) was applied --- in other words - at that room temp they could have looked at the gold all day under the highest level of magnification WITHOUT applying the electric field to extremely high levels & what they would have observed is that the "surface" of the gold was "not'" molten at the temp of the room

If you google - "what is considered to be room temperature" - you will find that it is an "agreed on range" for comfort in a room - that range is considered 68 - 72 F (20 -22 C)

In a room within that range temp I can melt a full ozt. (31.1 grams) with a MAPP gas torch & I wont change the temp of the room by even one degree - much let alone raise the temp above that range 

My point being (& as Dave said) I to can melt gold at room temp - & I can melt a whole lot more then just the surface of a ozt. --- & that's because the temp of the room has "nothing" to do with the gold melting - it's the energy (torch) "targeting" the gold that melts it --- in fact - I can melt gold at "less" the room temp


taking it a step further -if they had put the same gold under their scope & put a MAPP torch to it (instead of an electric field) - they would have observed the same thing --- the "surface" of the gold melting - "at room temp" (the surface being only a few atoms deep) & I am willing to bet that "surface" melting would take place within seconds - if not a second --- it would take place looong before the gold "started" to become molten to the naked eye 

Bottom line - they have proved two things - 1) gold at room temp is not molten - not even at the surface - 2) gold can be melted at room temp - BUT - it takes an energy source applied &/or targeted to the gold before becoming molten at room temp --- So really - all they proved is that energy is "required" in targeting gold in order for gold to reach a molten state - whether at a surface level or full blown melt down

So does gold melt at room temp --- yep :!: :!: :!: --- but ONLY if energy is applied/targeted at the gold

Therefore - IMO - this article is pure B.S. - smoke & mirrors --- or as a wise man once said - shenanigans and semantics --- because gold at room temp ALONE does not & will not make gold molten "at any level" - that is physics 101

Expensive lab gear was used to "apply" the electric field "before" their expensive scope observed the gold reaching a molten state (a few atoms deep) - without the electric field - their scope would have seen nothing other then the crystal formation of solid gold



> Further quote from the article;--- Because we can control and change the properties of the surface atom layers, it opens doors for different kinds of applications. For example, the technology could be used in different types of sensors, catalysts and transistors. There could also be opportunities for new concepts for contactless components



That "may" be true - but gold being molten at room temp "alone" is not going to open any of those doors & that's because gold is not molten at room temp - they will have to create technology (which will need to be plugged in) to achieve the molten state of gold they "hope" for to open the doors to the other suggested technologies --- it will still need to be plugged in to make it work 

Kurt


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## butcher (Dec 14, 2018)

Plasma torches cut steel (or melt steel) or many other metals at room temperature.


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## g_axelsson (Dec 16, 2018)

kurtak said:


> XRF ?
> 
> Kurt



XRF is X-ray Fluorescence, it messes with the inner electrons in atoms and those are not affected by puny melting point temperatures.

XRD = X-ray Diffraction is bouncing x-rays on atoms, if they are arranged in an ordered way then the x-ray is deflected in a very precise angle depending on the energy of the x-ray and the distance between the atoms.

You can do the same thing with high speed electrons, after all, particles and waves are the same thing in the quantum world.

When stuff melts the distance between atoms becomes random and the patterns made by X-rays bouncing off the crystal lattice disappears.

Göran


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## g_axelsson (Dec 16, 2018)

butcher said:


> Plasma torches cut steel (or melt steel) or many other metals at room temperature.


Excuse me, but that's just a stupid statement. The plasma and the steel being removed is way higher than room temperature. All that electrical power going into the plasma torch ends up as heat.
If you still believe that it cuts at room temperature, put your hand on the other side of the steel and see how bad it burns at room temperature.

Göran


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## g_axelsson (Dec 16, 2018)

kurtak said:


> anachronism said:
> 
> 
> > Well to be fair the melting point of gold is not room temperature no matter which site you look at or which reference document you choose to reference.
> ...



How hard is it to understand that the temperature of the room has nothing to do with the experiment. The "Room temperature" is roughly the temperature of the gold piece.

Temperature is a quite well defined physical entity. It is directly related to the vibrational energy in matter. If you put an electrical field around an object that doesn't affect the temperature. Just as pressure doesn't affect temperature but it affects the melting and boiling point of materials.
That is physics 101.

There are a lot of ways to measure temperature and one of the easiest is to look at IR-emission from an object. If the gold melted without starting to glow it in deed melted at a much lower temperature than the melting point says.

Göran


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## butcher (Dec 16, 2018)

g_axelsson said:


> butcher said:
> 
> 
> > Plasma torches cut steel (or melt steel) or many other metals at room temperature.
> ...



I can melt gold, at a room temperature of 72 degrees F, with a high-temperature plasma arc where the temperatures inside the plasma can range from 5,000K to 20,000K.
What is stupid about that statement?
I did not say the localized plasma arc or the ionization area was at room temperature.
What does the temperature of the room have to do with melting metals?
How is this statement different than if I said I can melt a few atoms of gold with a laser beam at a room temperature of 72 degrees F viewed under a microscope?
What does the temperature of the room have to do with anything here?


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## g_axelsson (Dec 16, 2018)

butcher said:


> g_axelsson said:
> 
> 
> > butcher said:
> ...


Please, explain to me then what you mean by "Plasma torches cut steel (or melt steel) or many other metals at room temperature."

If the plasma arc is at 5000-20000 K then it isn't room temperature. Room temperature is approximately 393K.

The report states that the gold melted while still at room temperature (probably slightly higher than 400K) 

If you use a laser beam, a plasma torch or a mapp torch to melt gold it still melts at around 1400 K. It is just different ways to increase the temperature (vibrational energy) in the gold up until the point where it melts.
Increasing the electrical field to get the gold melting at the surface at 400K is a totally different process. Apparently the binding energies at the surface are affected and the gold melts. And the molten gold is at room temperature while molten.

Another example of how the melting point can vary depending on external factors is the phase diagram of water, at 200MPa pressure water melts at -20C while under normal atmosphere pressure it melts at 0C.
http://www1.lsbu.ac.uk/water/water_phase_diagram.html
You could easily measure the temperature and while compressing water will heat it up slightly it is easily cooled down and it is the measured temperature that is entered in the diagrams.

Göran


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## nickvc (Dec 16, 2018)

Having followed this thread I have to say it’s falling into a world of semantics, let’s give this a miss now and get back to discussing recovery and refining :shock: :roll:


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## butcher (Dec 16, 2018)

The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point, the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at a standard pressure such as 1 atmosphere or 100 kPa.

Yes, I can boil or freeze water at room temperature nothing new here.

So we can melt a substance (excite the molecules energy level to break a rigid surface), under other conditions besides temperature.



As the energy in the molecules increases from a rise in temperature, the molecules start moving faster. Soon they have enough energy to break free of their rigid structure and start moving around more easily. The matter becomes a liquid.

Making of a few molecules move faster in a localized area with a laser beam under a microscope at room temperature is no surprise to me.

we can melt metal at room temp under pressure.
https://www.sciencealert.com/scientists-have-just-melted-a-solid-below-its-freezing-point

I cannot see what the excitement is about so they made a few molecules of gold move around or get excited under a microscope.

Actually, I have not been following this discussion very thoroughly, I guess I should read the article you guys are getting all molten over (excited over) before opening my jaw and pressing keys...


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## butcher (Dec 16, 2018)

http://sustainable-nano.com/2018/02/14/melting-temperature-depression/


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## g_axelsson (Dec 16, 2018)

That was two interesting articles, Butcher.

I don't know where you got the impression that they used a laser beam to zap the surface layer. It was a high electric field. The interesting thing in this discovery is that the melting point of gold was lowered about 1000K by applying an electric field, as I understand it no one has done that before so it's a discovery. It might not be revolutionary but an incremental step forward of our understanding of nature. In the end it's hard to see what becomes an important discovery or not. In the beginning the laser was called "A solution looking for a problem" and now it's used all over.



butcher said:


> As the energy in the molecules increases from a rise in temperature, the molecules start moving faster. Soon they have enough energy to break free of their rigid structure and start moving around more easily. The matter becomes a liquid.


But in this case the gold atoms doesn't move any faster, they melt at "room temperature".

If this effect is discovered in gold then it ought to exist in other materials too. Maybe partial melting of silicon could create a ultra pure surface free of gallium, that could create a new generation of XRF guns (uses Si-crystals as detectors but gallium is hard to remove).
Micro machining could be another area where a localized melting of material could be a great tool.

Personally, I'm just fascinated by learning more about nature.  

Göran


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