Raman Single Crystal Studies of Spinel TypeMCr2S4(M=Mn, Fe, Co, Zn, Cd), MIn2S4(M = Mn, Fe, Co, Ni), MnCr2 -2xIn2xs4 and Col -,CdxCr2S4" The Raman spectra of single crystals (grown by chemical vapour transport with I,, AICI,, CrCI, and InCI, as transporting agents) and polycrystalline samples of spinel type MCr,S, (M = Mn, Fe, Co, Zn, Cd), MIn,S, (M = Mn, Fe, Co, Ni), MnCr,-,,In,S, and Co,-,Cd,Cr,S, were recorded. The main results obtained are (i) large resonance enhancement effects, (ii) breakdown of the translation symmetry in inverse spinels (MIn,S,), which results in band broadening and the observation of more bands than group theoretically allowed, e.g. a clustering mode ( A in both spinel solid solutions and partly inverse ternary spinels and (iv) frequency shifts of the observed bands caused by the tetrahedrally coordinated metal ions due to mass effects (F,# modes) and both bonding (ionic charge, covalency) and repulsion interactions ( A at about 250 cm-', (ii) two-mode behaviour of the breathing modes of the tetrahedral MS, units ( A modes).