Magnetic properties of MM'X (M= Mn, M'=3d or 4d metal, X = P, As, Si, Ge) compounds with hexagonal or orthorhombic crystal structure

Magnetic properties of the MnFe1-xCoxR, MnRh1-xCoxAs, (Mn1-xCox)(2)P and MnCoSixGe1-x intermetallics are compared based on experimental studies and KKR full potential calculations. Modifications introduced in the tetrahedral but not in the pyramidal sites of their metallic sublattices play the main role in variations of magnetic interactions. For the (Mn1-xCox)(2)P series that was shown not only in the composition, temperature and external magnetic field dependencies but also in the pressure variation of the magnetic interactions. The latter was confirmed also by electronic band structure calculations. For MnCoGe the spin and the orbital component of the magnetic moment is reported for the first time.