Magnetic phase transitions in Mn5-xTxSi3 alloys

The magnetic properties of a series of the intermetallic compound Mn5-xTxSi3 with T=3d transition metal Ti, V, Cr, and Ni have been examined as a function of the magnetic field (0-12 T) and temperature (2-300 K). The alloys have the same hexagonal D8(8) crystal structure as Mn5Si3 with very little change in lattice spacing. The magnetization measurements show that the substitutional elements produce a variety of effects, dramatically altering the field and temperature dependence of the AF1/AF2 and AF2/paramagnetic transitions. It is assumed that since the Mn-Mn distances in the parent alloy are all near critical values for instability the substitution on to Mn sites interferes significantly in the Mn-Mn interactions. (C) 1997 American Institute of Physics.