Spectroscopic Properties and Magnetic Phase Transitions in Scheelite MICr(MoO4)2 and Wolframite MICr(WO4)2 Crystals, where MI=Li, Na, K, and Cs

We present a spectroscopic overview of Cr3+ ions in MICr(MO4)2 scheelites, a prospective crystals lasing in the infrared region, and new magnetic materials exhibiting antiferromagnetic ordering (MI=Li, Na, K, Cs and M=Mo and W). The infrared, Raman, electronic absorption, and fluorescence measurements were conducted at temperatures ranging from 77 to 300 K. The ESR, magnetic susceptibility, and magnetic field dependence were studied in the 4–300 K range and discussed in terms of Cr3+ ion properties in these compounds. The magnetic transitions are reported for all compounds studied.