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Local environment effects on hyperfine interactions in disordered transition metal systems

 

Supervisor:      Marcus Ekholm

Level:              adaptable to Bachelor or Master level

Prerequisites:  Physics of condensed matter I (TFFY70) Quantum Mechanics (TFFY54)

Description:

In solid matter, atoms of the same kind but with unlike neighbours may exhibit very different properties [1]. This effect is frequently seen experimentally, e.g., in spectroscopic measurements [2]. A theoretical understanding of the relation between the microscopic local environment and observable properties is therefore of prime importance in modern materials science.

! In transition metals such as Fe and Ni, the electronic charge density at the nucleus is spin polarised, causing a local magnetic field interacting with the nuclear magnetic moment. In turn, this gives rise to a hyperfine Zeeman splitting of the nuclear energy levels, which is readily measured with Mössbauer spectroscopy. This is a powerful tool to extract information on the local environment in multicomponent systems [3].

! Within this project we will use state-of-the-art computational tools to investigate the relation between the local environment and the local magnetic fields giving rise to hyperfine splittings in disordered FeNi-alloys. We will model the alloy system by including a large number of atoms in our simulations. This will allow us to study the distribution of the fields in the disordered alloy and to extract statistical data.

As a student, you will learn how to use modern ab-initio computational tools employed in academia as well as industry, such as the Vienna ab-inito simulation package [4] and the Wien2k code [5]. You will also gain experience in handling large-scale supercomputer simulations.

  1. I.A.AbrikosovandB.Johansson,Phys.Rev.B57:14164(1998)

  2. R.J.Coleetal.,Phys.Rev.Lett78:3777(1997)

  3. N. N. Greenwood and T. C. Gibb, Mössbauer Spectroscopy , Chapman and Hall Ltd,

    London, 1971

  4. http://www.vasp.at /

  5. http://www.wien2k.at /


Responsible for this page: Fei Wang

Last updated: 12/30/13