Antiferromagnetic rare-earth ordering in the intermetallic compounds R₂Pd₂In (R = Pr, Nd)

The intermetallic compounds R₂Pd₂In of the light rare earths R = Pr, Nd were investigated by means of powder neutron diffraction in the temperature range from 1.6 K to 15 K. The chemical structure is of Mo₂FeB₂ type according to the space group P4/mbm. Antiferromagnetic rare-earth ordering of modulated type corresponding to k = [0,0,1/2] and [1/4,1/4,0] was established below the Néel temperatures T_N = 5 K and 8 K for R = Pr and Nd, respectively, in contrast to k≈[0.22,0,0] and k = [0,0,0] of the antiferromagnetic and ferromagnetic, nonstoichiometric Ce₂Pd₂In systems.