why there is no diffusion exist in metals?

why there is no diffusion exist in metals?

Do you have any reference for your assertion?

I believe diffusion in metals does occur. Here is a whole book on the subject. If you search on diffusion in metals, you will find several other references.

Amazon.com: Diffusion in Solid Metals and Alloys / Diffusion in festen Metallen und Legierungen (Landolt-Börnstein: Numerical Data and Functional Relationships in ... Technology - New Series / Condensed Matter) (9783540508861): H. Bakker, H.P. Bonzel

John

please read first para of DIFFUSION topic of following link:
Integrated Electronics - Millman & Halkias - Google Books

---------- Post added at 20:53 ---------- Previous post was at 20:51 ----------

@jpanhalt
please read first para of DIFFUSION topic of following link:
Integrated Electronics - Millman & Halkias - Google Books

I checked your links and cannot find where any of them say diffusion can't occur with metals. It is a simple fact that diffusion does occur. Can you perhaps use cut and paste (e.g. use print screen and photoediting) to post the paragraph where is says diffusion doesn't occur?

I suspect there is some limiting condition to explain that statement.

John

Edit: Here is a primary reference to a classic experiment showing diffusion of gold into lead: Self-diffusion in Solid Metals : Abstract : Nature

Pure semiconductors have high resistance and have no use. Diffusion in semiconductors is done to change their electrical properties like resistance and to use them to make a useful devices. Metals are already good conductors. So diffusion is not done in metals this doesn't mean diffusion is can't be done in metals. But point is why to do diffusion in metals? Is there any use of doing so?

The original poster said nothing about semiconductors.

Although diffusion of gold into lead may not be a useful property for semiconductors, there are circumstances in which metal diffusion in the solid state is a disadvantage that one must be aware of. The first link describes a case on point:

**broken link removed**

This is a more general discussion of gold or silver diffusion in indium:

Phys. Rev. 151, 495–498 (1966)
Interstitial Diffusion of Gold and Silver in Indium (abstracted here: Interstitial Diffusion of Gold and Silver in Indium)

John

One example......
Diffusion in highly alloyed special steels
Defects in lattice structure
Defects of a stack in the layers of atoms is called dislocation.
Actual metal crystals are not error-free and regular, but rather there is always punctuated a stack of defects,
which may have empty atomic positions, ie vacancy or placement of a foreign atom crystal.
The number of vacancies will increase by cold working with temperature rises.
The acceleration of the layer changes taking place in alloys and the diffusion , such as loss of carbon
or the dissolution of the coating material in various thermal surface treatments of alloys .

first para:
In addition to a conduction current, the transport of charges in semiconductor may be accounted for by a mechanism called diffusion, "NOT ORDINARILY ENCOUNTERED IN METALS" .

I do not have Millman and Halkias and cannot access it from the link you gave. However, the excerpt you quote suggests that we are talking about two different things.

In the one case, your original post stated that diffusion does not occur in metals. With reference to diffusion of metal atoms from one metal into another, that simply is not true. Such diffusion does occur, albeit slowly compared to liquids and gases, as pointed out by myself and others in this thread.

On the other hand, it appears you are really talking about the mechanism of electrical conduction in metals versus semiconductors. I am not knowledgeable in that area, but it seems entirely reasonable that there are differences in the predominant mechanism. See:
Fermi level - Wikipedia, the free encyclopedia

Source: Semiconductor - Wikipedia, the free encyclopedia
The effective mass is important as it affects many of the electrical properties of the semiconductor, such as the electron or hole mobility, which in turn influences the diffusivity of the charge carriers and the electrical conductivity of the semiconductor.

Click to expand...

Finally, I would interpret the simple phrase, "Not ordinarily encountered in metals," to mean that the mechanism for conduction being referenced may occur in metals or cannot be excluded as occurring in metals, but it is not the predominant mechanism in metals. Unfortunately, without access to that book, I cannot say more about the context of that statement.

John