We studied the pressure dependence of the magnetoresistance in the magnetic semiconductor MnS2. We know that MnS2 undergoes a pressure induced structural transition associated with high-spin to low-spin transition at about P = 11 GPa. The magnetoresistance which is negative at lower pressure crosses over to positive value at higher pressure. How can we understant the phenomenon?
Briefly, it has to do with the Fermi surface topology, with the change in the balance between the contributions of the electron and hole orbits as a consequence of applied pressure.
I was wondering whether we ca associate positive and negative magnetoresistances with the other physical properties of the crystal. Can one for example say that the positive magnetoresistance is characteristic of metallic or insulating or semiconducting state and can we say similar things in the case of negative agnetoresistance? Also where can I find some derivation of magnetoresistance in terms of some known measured parameters.
For magneto-resistance, the classic paper is by Sondheimer and Wilson (Proc. Roy. Soc. London, A190, (1947)). Similar derivation, based on the Boltzmann equation, can be found in the books by Ziman (both in Electrons in Metals and Principles of the Theory of Solids). A derivation of the expression for the magneto-resistance based on the Kubo formula can be found in the paper by Kontani whose link I attach below.
Magneto-resistance is also a focus of attention in the considerations regarding disorder, localisation as well as the Kondo problem. See, for instance, the paper by Strong, Clarke and Anderson, Magnetic Field Induced Confinement in Strongly Correlated Anisotropic Materials (Phys. Rev. Lett. 73, 1007 (1994)), whose link I also attach below. If interested, Anderson has a collection of the relevant papers in his book A Career in Theoretical Physics, 2nd edition (World Scientific, Singapore, 2004). Related to the problem of localization, I warmly recommend the book Green's Functions in Quantum Physics, 3rd edition (Springer, Berlin, 2006), by Economou.
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.64.054413
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.73.1007
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Semiconductor