Optical spectroscopy of a chromium doped (CH3)(2)NH2Al(SO4)(2)center dot 6H(2)O single crystal in the ferroelectric phase

The chromium doped (CH3)(2)NH2Al(SO4)(2) . 6H(2)O crystal was obtained from solution by a slow evaporation method at 303 K and investigated in the ferroelectric phase below 150 K using optical spectroscopy. It was found that the Cr3+ ions in the crystal are situated in a strong crystal field in which the (2)E State is the lowest. A single narrow R line associated with the (2)E-(4)A(2) phosphorescence indicates an undistorted octahedral Cr3+ Site in the host lattice. The O-H bonds in the first coordination sphere induce efficient nonradiative transitions from the (2)E emitting state and the Cr3+ emission is completely quenched at temperatures above 150 K.