Crystal-fields and magnetic exchange in ternary rare earth intermetallic compounds

Program Code: 
1892
Contact: 

Prof Sean Cadogan (s.cadogan@adfa.edu.au)

Description of Work: 

Objectives:

Ternary rare-earth intermetallic compounds are important from both theoretical and applied points of view. These compounds usually contain a transition element and a metalloid element, in addition to the rare-earth, and this combination allows us to study the role played by the f-d-p electrons in determining the magnetic stucture of a compound. We can also probe the fundamental magnetic exchange and crystal-field interactions across a series of related compounds.

The crystal structures of ternary compounds can be quite complex, involving more than one rare-earth site, and in some cases the different rare-earth sites show quite independent magnetic behaviour from one another, which is somewhat unusual in metallic systems. In this project we will investigate the magnetic exchange and magneto-crystalline anisotropy mechanisms in ternary rare-earth intermetallics in terms of fundamental building blocks whose local point symmetries form the basis for the behaviour of the more complex ternary structures.

This work is mainly theoretical/computational and will involve the development of computer programs to carry out crystal-field and exchange calculations for a variety of ternary structures.

Description of Work:

  • Analysis of the structural information on various series of ternary intermetallics;
  • Development of computer programs to carry out crystal-field and magnetic exchange calculations;
  • Determination of the underlying fundamental crystallographic symmetries of complex ternary structures;
  • Explanation of the magnetic and structural behaviour of complex ternaries in terms of local exchange and crystal-field interactions.