Crystal Structure of New Heusler Compounds

Heusler compounds are promising materials in many fields of contemporary research. The spectrum of their possible applications ranges from magnetic and magneto-mechanical materials over semiconductors and thermoelectrics to superconductors. An important feature of the Heusler compounds is the possibility of controlling the valence electron concentration by partial substitution of elements. On the other hand, the properties also depend on the degree of ordering of the crystal structure. In general, Heusler compounds crystallize in the Cu2MnAl-type structure but in many cases certain types of disorder are observed. In this paper a detailed description of the different types of disordered structures is given. Additionally, the synthesis of new Heusler compounds is reported. The prepared compounds contain ternary Cr-, Rh-, Ru-, Ni-, Pd-, and Pt-based Heusler systems as well as quaternary Co-2-based compounds and compounds of the general formula XX' YZ. The crystal structure was determined by XRD measurements and the structural ordering of the compounds is discussed.