Ferro‐Nonmagnetic Transformation of Mn Alloys with CaC2 Type Structure

The magnetization, magnetic susceptibility, electrical resistivity and lattice parameter for the substituted (Au1−xPdx)2Mn and Au2(Mn1−xCrx) systems were measured. In the case of (Au1−xPdx)2Mn, x=0.02 and 0.05, Hth and c/a increase with increasing of Pd, while χi and a decrease. On the other hand for Au2(Mn1−xCrx), x=0.05 and 0.10, the Hth decreases with increasing Cr and for x=0.10 the Hth tends to zero at the T*=240 K. However a and c/a do not change with Cr. The helical angle which is estimated from our experimental results increases with increasing Pd, but decreases with increasing Cr.