Search results

We present results of the exchange interactions and Curie temperatures in some Cr-based chalcogenides and pnictides. The calculations are performed mostly for Zinc Blende (ZB) structure with the lattice parameter varying between 5.45 and 6.6 Å, appropriate for some typical II-VI and III-V semiconducting substrates. Electronic structure is calculated via the linear muffintin-orbitals method and disorder effects, when appropriate, are taken into account via the coherent potential approximation. Calculated exchange interactions are used to estimate the Curie temperature by employing the mean-field and the random phase approximations. For CrTe we compare the results of the ZB and Rock-Salt (RS) structures.

The electronic properties, exchange interactions, Curie temperatures and transport properties of random quaternary Heusler alloys (Ni, Cu)₂MnSn are studied by means of density-functional calculations over the entire range of dopant concentration. Results agree qualitatively as well as quantitatively with the available experimental data. The residual resistivity is found to obey the Nordheim rule, indicating weak-scattering regime. The temperature-dependent spin-disorder resistivity is found to be described well via the disordered model of local moments. Effect of pressure on the Curie temperature and the resistivity is also explored.