Magnetic structure of short-range ordering in intermetallic antiferromagnet Mn₃RhSi

Magnetic pair distribution function (mPDF) of intermetallic antiferromagnet Mn₃RhSi is estimated from the powder neutron diffraction data. The mPDF exhibits negative peak at about r = 2.7 Å corresponding to the nearest neighbor Mn-Mn distance above the antiferromagnetic transition temperature T_N. Below T_N, the mPDF is a superposition of the mPDF with the negative peak at about r = 2.7 Å and the mPDF calculated from the antiferromagnetic structure which is determined by the previous neutron diffraction study, indicating the coexistence of the short range ordering and the antiferromagnetic long range ordering. The mPDF of the short range ordering is not reproduced by the magnetic structure model with the symmetry consistent with that of the crystal structure. The possible magnetic structure which can reproduce the observed mPDF of the short range ordering is proposed. (author)