Structural, Optical, Magnetic, and Dielectric Properties in Hybrid Solid Solutions of Zn_αNi_1-α(en)₃Ag₂I₄ (0 < α < 1) by Varying the Relative Zn/Ni Content

The hybrids of M(en)₃Ag₂I₄ (M = Zn or Ni) are isostructural to each other and crystallize in space group P6₃22 with quite similar lattice parameters. The hybrid solid solutions Zn_αNi_1-α(en)₃Ag₂I₄ (0 < α < 1) have been prepared via self-assembly in the mixed N,N-dimethylformamide solution of AgNO₃, KI, and ethylenediamine, meanwhile, with certain relative amount of [Zn(en)₃]²⁺ and [Ni(en)₃]²⁺ ions at ambient condition. All hybrid solid solutions are isostructural to the parent hybrids M(en)₃Ag₂I₄ (M = Zn or Ni). The UV-vis-near IR diffuse reflection spectra in solid state, thermogravimetric analysis, variable-temperature magnetic susceptibility, and dielectrics have been investigated for Zn_αNi_1-α(en)₃Ag₂I₄ (0 < α < 1). The intensity of bands centered at 540 and 860 nm in UV-vis-near IR spectra, arising from the d-d electron transition in Ni²⁺ ion, as well as the Curie constant decreases linearly with the molar fraction of Zn (α)/Ni (1 - α), whereas the c-axis length, the C-N and C-C bond lengths in the ethylenediamine, the frequency-independent dielectric permittivity and the onset temperature of dielectric relaxation, and so forth show nonmonotonical alternation with the fraction of Zn (α)/Ni (1 - α) in the solid solution, and the origin for these differences is further discussed.