The structure of the paramagnetic impurities in triglycine sulfate single crystals

Abstract

ENDOR investigations of the bis(glycinato)-Cu(II) (NH 2CH 2COO) 2Cu and bis(glycinato)-oxo-V(IV) (NH 2CH 2COO) 2VO complexes in the ferroelectric triglycine sulfate (TGS) single crystals are reported. Magnetic hyperfine constants of the ligand nuclei are given. The ENDOR investigati confirm the conclusion derived from EPR studies that the copper and vanadyl ions occupy interstitial lattice sites forming bis(glycinato) complexes wit triclinic symmetry C 1. Molecular theoretical calculations of the EPR and ENDOR parameters of different paramagnetic impurities in TGS were performe using the self-consistent charge and configuration (SCCC) version of the extended Hückel theory (EHT). By using perturbation theory the parameters of the spin hamiltonian were determined.