Exploring the Physics of Fermi Level in Metals

[Assaf Peled]

Hi, a question please:

Do all metallic substances have an equal Fermi energy level (at a constant T) ?
If not, what will happen (before equilibrium) if one "fuses" together two bulks of metal with different Fermi
levels (as in a PN junction) ?

Since there's an abundance of energy states available around the Fermi level in metals, I would consequently expect electrons to flow between the bulks until an equilibrium is reached. On the other hand, I sense a hole in my little theory here.

Many thanks.

A.

 

[nasu]

No, they don't. Electrons will indeed be transferred between the two metals. See Peltier effect.

 

[ZapperZ]

Hi, a question please:

Do all metallic substances have an equal Fermi energy level (at a constant T) ?
If not, what will happen (before equilibrium) if one "fuses" together two bulks of metal with different Fermi
levels (as in a PN junction) ?

Since there's an abundance of energy states available around the Fermi level in metals, I would consequently expect electrons to flow between the bulks until an equilibrium is reached. On the other hand, I sense a hole in my little theory here.

Many thanks.

A.

There's something called a "contact potential" when such metals are in contact with each other, very much similar to a PN junction as you suspected.

This effect is made use of in the Kelvin Probe technique of measuring contact potential and Fermi energy in metals.

Zz.

 

[bluejay27]

No, they don't. Electrons will indeed be transferred between the two metals. See Peltier effect.

To be more explicit, the conduction band and insulation band overlap for two metals allowing for electrons to move freely in a metal.