Electronic spectrum and magnetic properties of CsMnBr3

The polarized crystal spectrum of CsMnBr3 and manganous ion doped into the isostructural magnesium salt, CsMgBr3, have been investigated in the 15 000–30 000 cm−1 region. The general spectral features are very similar to those reported for (CH3)4NMnCl3. The intensities of the ligand field transitions appear to be strongly affected by exchange interactions, since these intensities are quite dependent on the manganese ion concentration. The magnetic susceptibilities of powdered samples of CsMnBr3 and CsMg0.92Mn0.08Br3 have been investigated in the 77–300°K range. The CsMnBr3 obeys the Curie&Weiss law above 190°K, but deviates significantly at lower temperatures. The dilute sample, CsMg0.92Mn0.08Br3, shows near Curie law behavior. The magnetic properties indicate the presence of strong antiferromagnetic coupling in CsMnBr3.