Some Neutron-Diffraction Investigations at the Nuclear Center of Grenoble

In orthorhombic CrRO3 (R=rare earth and Y), Cr spins are ordered in a G mode between TN 282°K for R=La, to 112°K for R=Lu. The rare-earth ordering is coupled to the Cr-spin ordering, with the exception of terbium. In the magnetoelectric compound Fe1.15Ga0.85O3, four sites are available for cations, one of these mainly occupied by Ga. Neutron-diffraction and magnetic-susceptibility measurements give evidence of a ferrimagnetic ordering. Tetragonal FeS shows no evidence for magnetic ordering by neutron diffraction and Mössbauer effect down to 1.7°K. The CrS-MnS solid solution has NaCl type. First kind of facecentered magnetic ordering is observed.