How to make Resisitivity vs. Temperature graph from in-lab measurements

[JosephK]

We used a wheatstone bridge, which is an electric circuit consisting of four resistors.Two of the resistors are known, one resistor is a large "resistor" with dials that control the resistance, and the fourth resistor can either be a metal or semiconductor. The metal was heated to about 290 °C.

As the metal cooled, I moved a metal slider across a metal line so that the ammeter read zero and we recorded the position of the slider every 5 degrees or so.

A sample of the data is:

Temperature (°C) Ratio (cm)
190 89.7
185 87.7
180 87.2
175 85.9
170 84.6
165 83.5
160 81.6
155 80
150 77.9

This is for a semi conductor. When I looked in a Intro to Physics book, I saw a rho (resistivity) verses temperature graph for a semiconductor. Now I wonder if I have all the data needed to make my own. If not, what can I do in this lab to obtain the necessary data?


Also, I need to understand what "Fermi-energy" is. What are phonons? What is bandstructure, energy levels of electrons in solids, fermi distribution, densisty of states?

I know what scattering of electrons is. The intro to physics book says that, when a metal is hot, the ions vibrate back and forth faster, and it is difficult for an electron to go through without getting pushed back.

 

[member 553083]

But what is the actual mechanism?To answer your questions, Fermi energy is the energy level at which half of the electrons in a given system are occupied. Phonons are quasiparticles that represent the vibrational energy of molecules or atoms in a solid. Bandstructure refers to the arrangement of energy levels within a material, and it is related to the allowed energies of electrons in the solid. The Fermi distribution is a mathematical equation that describes the probability of an electron being at a certain energy level in a given material. The density of states is the number of electrons that can occupy a certain energy level in a material. Scattering of electrons occurs when the electrons interact with impurities in the material or with other electrons. The scattering causes the electrons to be deflected from their original paths and thus reduces their speed and energy.