Variable temperature EPR study for confirming dynamic Jahn-Teller distortion in Cu(II) doped zinc ammonium phosphate hexahydrate

Single crystal EPR rotations done about the three mutually orthogonal axes at 300 and 143 K for copper(II) doped zinc ammonium phosphate hexahydrate indicate that the spin Hamiltonian parameters (g and A) are highly temperature dependent, whereas their direction cosines are not to that extent. Powder spectra of the sample recorded from 300 to 77 K confirm dynamic Jahn-Teller distortion for Cu(II) ion. Two out of three g/A values are temperature dependent, whereas the third one almost remains constant in the temperature range. Various Jahn-Teller and covalence parameters are calculated. (C) 2003 Elsevier Science Ltd. All rights reserved.