Explaining electrical resistivity behaviour from phonon perspective

[y4ku24]

Hello everyone.

This question may sound naive, but since I am relatively new to the subject, I would like to ask for some clarification related to phonon and electrical resistivity.

As most of you might be aware of, electrical resistivity of crystalline metals increases due to increase in temperature. I am currently working with some non-crystalline metals, and the data show a high electrical resistivity at RT, and a linear decrease due to increase in temperature.

Since both are conductors, could this two contrary phenomenon be explained from a phonon perspective?

Thank you in advance.

 

[transience]

From my (3rd year undergraduate) understanding phonons increase the resistivity for metals because they scatter electrons. Have you considered defects? They are known to decrease as temperature is increased and I would expect that a noncrystaline metal would have plenty of them, it would depend upon the temperature ranges that you are dealing with.

 

[y4ku24]

To transcience: Hm,seems like a considerable explanation. Will look up about it. Thank you.

 

[sokrates]

Why are defects decreasing as T is increasing?

Just increasing T doesn't heal anything, for annealing to remove defects, the lattice should be heated and slowly cooled.

y4ku24 - I don't think your data can be so easily explained by phonon scattering. Maybe you want to check percolation theories to see what's going on.

Transport in disordered systems (like non-crystalline metals) is very different than the idealized transport theory where the lattice is perfectly periodic, etc...

 

[hiyok]

Hi, y4ku24, would you say a little more about the materials you are measuring ? Because, several factors may affect temperature dependence of resistivity, depending on the electronic structure of the material.

 

[y4ku24]

TO hiyok: My material is an amorphous metal, with composition of Zr55Ni5Al10Cu30. It is known as metallic glass, and has some advantages compared to common metals such as high strength and high corrosion resistance, provided that it stays as an amorphous metal.
The materials looks like a common alloy, but in the atomic scale it has glassy characteristics such as the existence of glass transition temperature.

Hope that helps.