MOSSBAUER STUDY OF SN-119 HYPERFINE INTERACTIONS IN THE KTI1-XSNXOPO4SYSTEM

The first Mossbauer study of hyperfine interactions of Sn-119 nuclei i n the complex ferroelectric oxides KTi1-xSnxOPO4 is reported. A one-to -one correspondence between the hyperfine interaction parameters and t in atom arrangement in cis and trans positions of the structure has be en established. The electric-field gradient at Sn-119 nuclei is shown to be dominated by the contribution of valence electrons in the hybrid ized p and d orbitals. A linear correlation between the quadrupole dis placement of the spectrum components and the average Sn-O distances ha s been revealed. The Mossbauer line shift data were used to estimate t he number of valence s electrons of Sn4+ ions occupying the cis and tr ans positions throughout the x range covered. (C) 1998 American Instit ute of Physics.