Hyperfine Interactions in Copper Lattice Sites of Antiferromagnetic Compounds Representing the Analogues of Superconducting Copper Metal-Oxide Compounds

摘要

Emission Cu-61(Ni-61) Mossbauer spectra of dielectric metal-oxide compounds of divalent copper with molecular formulas Ca1 - xSrxCuO2, Ca2CuO2Cl2, SrCuO2, Sr2CuO2Cl2, YBa2Cu3O7 - (x), La2 - xSrxCuO4, and Nd2 - xCexCuO4 correspond to the quadrupole and Zeeman interactions of the Ni-61 nuclei with local fields at the copper lattice sites, whereas the spectra of superconducting metal-oxide complexes correspond to the interaction of the quadrupole moment of the Ni-61 nuclei with the tensor of the electric field gradient (EFG). For both groups of metal oxides, linear dependences of the quadrupole interaction constants on the calculated values of the principal component of the lattice EFG tensor in the copper lattice sites are observed both on the Ni-61 nuclei (data of the emission Mossbauer spectroscopy on the Cu-61(Ni-61) isotopes) and on the Cu-63 nuclei (data of the nuclear magnetic resonance on the Cu-63 isotope). This fact is explained by the constant values of the valence component of the EFG for both the Ni-61(2+) and Cu-63(2+) probes in all metal-oxide complexes of divalent copper.