Institute of Applied Physics

Nonlinear Systems and Patternformation (NSPF) - Magnetism - Material Science - Applied Physics

Nonlinear Systems and Pattern Formation (NSPF) - Magnetism - Materials Science - Applied Physics

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3. Materials Science

See also Research

Fig. 3.1
Schematic diagram of the apparatus to pull single crystals of rare earth intermetallic compounds

In this chapter we list various  investigations that have to do with material preparation and properties of materials.

  • Elastic constants
    The strength of the interaction of dislocations with impurities in metals partially depends on the change of elastic constants with impurity concentration. Therefore, it is of considerable interest to know about the change of these constants with concentration. On this background, the following work has been performed [1]:
    • Preparation of single crystals of Ag-Al  and Ag-Au  by the Bridgeman method and control of the quality of the crystals using standard methods from metallurgy.
    • Determination of the  elastic modules of rods of Ag-Al  and Ag-Au  single crystals being oriented in  <100>, <110> and <111>  crystallographic direction and evaluation if all three single crystal elastic constants as a function of the impurity concentration.
    • The results are analysed in terms of a simple theoretical model.
    • Also in the context of the plastic deformation of Ir single crystal are of  interest. Therefore, for the first time the single crystal modules have been determined of this metal. Thereby the  single crystals were prepared by the zone melting technique. This work is considered as one of the highlights in the field of material science [2].
  • Single crystals
    Another highlight is the first preparation of single crystals of rare earth intermetallic compounds [4]. Thereby the Bridgeman technique has been applied using a tungsten crucible and appropriate germs to define the crystallographic orientation of the final crystal. The diameter of the latter measured about 1 cm und the length of the crystals  was of  the order of some cm. The technique was describe somewhat later also in [9]. We mention that the work on the magnetic properties of rare earth intermetallic compounds, to large extent, is based the availability of such crystals.
  • Electrical resistivity
    Finally, we mention that several attempts have been made to get a deeper understanding of the low temperature resistivity of alloys in the context of so called spin-fluctuations [5,6,8].

© 2011 Institute of Applied Physics
Working group Nonlinear Systems and Patternformation - Magnetism - Material Science - Applied Physics

© 2011 Institute of Applied Physics
Working group Nonlinear Systems and Patternformation - Magnetism - Material Science - Applied Physics
Corrensstr. 2· D48149 Münster
E-Mail: purwins@uni-muenster.de