Electronic spectra of [N(CH3)4]2CoCl4 microcrystals in thin films

Optical absorption spectroscopy was used to study [N(CH 3 ) 4 ] 2 Co x Zn 1–x Cl 4 (x = 0.75, 0.50, 0.25) and [N(CH 3 ) 4 ] 2 CoCl 4 microcrystals in the thickness range 10 ≤ d < 100 μm. Weakening of the crystal field was observed with a decrease in the [N(CH 3 ) 4 ] 2 CoCl 4 crystal thickness. Both the reason for the dependence of the absorption band shifts in the visible region on the [N(CH 3 ) 4 ] 2 CoCl 4 crystal thickness and the manifestation of a size effect in crystals with an incommensurate superstructure were considered.