Fundamental magnetism and magnetocaloric effects in rare earth alloys and compounds

Program Code: 
1892
Contact: 

Dr Wayne Hutchison (w.hutchison@adfa.edu.au)

Description of Work: 

Objectives:

Rare earth intermetallic alloys such as RNiAl4 (R = rare earth) have fundamentally interesting magnetic properties, including metamagnetism. Additionally, it has been discovered recently that the magnetic transitions in these alloys show large magnetocaloric effects, and could be the basis for refrigeration schemes. Rare earth compounds such as HoF3, an enhanced nuclear paramagnet also show potential for use in very low temperature refrigeration. This project will involve further fundamental study of such compounds in order to identify potential refrigerants and develop possible schemes for using such alloys.

Description of Work:

  • Synthesis of alloys and compounds with characterisation by standard techniques such as x-ray diffraction;
  • Carry out measurements to characterise magnet materials using a number of appropriate techniques including heat capacity, magnetisation and susceptibility, neutron diffraction, and low temperature (millikelvin) nuclear orientation;
  • Select the most suitable materials for refrigeration in various temperature regimes. Develop and test prototype refrigeration schemes.