OPTICAL-ABSORPTION SPECTRA OF NICKEL AND COBALT-DOPED ZNKPO4-CENTER-DOT-6H(2)O

Optical absorption spectra of nickel and cobalt doped ZnKPO4 . H2O (ZP PH) crystals are recorded both at room and liquid nitrogen temperature s. The bands of the nickel doped ZPPH crystal are characteristic of Ni 2+ in octahedral symmetry with spin-orbit interaction whereas those of Cobalt doped ZPPH crystal are characteristic of octahedral symmetry w ithout any distortion or spin orbit interaction. The following crystal field (Dq), Inter-electronic repulsion (B & C) and spin-orbit interac tion (xi) parameters are evaluated: Ni2+: ZPPH double right arrow Dq = 900, B = 890 C = 3800 and xi = 600 cm(-1). Co2+ : ZPPH double right a rrow Dq = 930, B = 925, C = 3790 cm(-1).