Magnetic structure of cubic spinels MnxCr3−xO4 (x=1.0−1.6)

Neutron diffraction study on samples Mn_xCr_3?xO₄ with x=1.0, 1.2, 1.4 and 1.6 has been performed at temperatures below ～40 K where magnetic ordering is present. At 5 K the structure of the MnCr₂O₄ compound was found to be a general LKDM magnetic spiral with the propagation vector deviating by 13.3″ from the 110] axis. This results differs from previous findings. At about 16 K the structure becomes collinear. In samples higher content of manganese the magnetic structure is collinear over the whole temperature region (5–40) K, i.e. in the sense of long range ordering. However, a short range ordering of the transverse components of the spins is present both in these samples and in MnCr₂O₄ above 16 K.