Bis-Tetrapropylammonium tetrabromozincate was synthesized and characterized by X-ray powder diffraction,as well as vibrational and impedance spectroscopy.Rietveld’s refinement of X-ray diffractogram confirmed the cry...Bis-Tetrapropylammonium tetrabromozincate was synthesized and characterized by X-ray powder diffraction,as well as vibrational and impedance spectroscopy.Rietveld’s refinement of X-ray diffractogram confirmed the crystallization of the compound through the monoclinic system(space group C_(2/c)).A temperature study of Raman scattering revealed two phase transitions at approximately T_(1)=340 K and T_(2)=393 K.The wavenumber and the line width’s evolution as a function of temperature showed some peculiarities associated with these transitions,which suggests that they are governed by the reorientation of the organic part[N(C_(3)H_(7))_(4)]+.The complex impedance plotted as a double semicircular arc in the studied temperature range and the centers of these semicircles lie below the real axis,which indicates that the material is an on-Debye type.These semicircular arcs are related to the bulk and the grain boundary effects.Furthermore,the alternating current conductivity of[N(C_(3)H_(7))_(4)]_(2)ZnBr_(4)obeyed Jonscher’s law:σ_(AC)(ω)=σ_(dc)+Aω^(s) and the conduction could be attributed to the correlated barrier hopping(CBH)model in both region(I)and(II)and the Non-overlapping Small Polaron Tunneling(NSPT)in region(III).展开更多
文摘Bis-Tetrapropylammonium tetrabromozincate was synthesized and characterized by X-ray powder diffraction,as well as vibrational and impedance spectroscopy.Rietveld’s refinement of X-ray diffractogram confirmed the crystallization of the compound through the monoclinic system(space group C_(2/c)).A temperature study of Raman scattering revealed two phase transitions at approximately T_(1)=340 K and T_(2)=393 K.The wavenumber and the line width’s evolution as a function of temperature showed some peculiarities associated with these transitions,which suggests that they are governed by the reorientation of the organic part[N(C_(3)H_(7))_(4)]+.The complex impedance plotted as a double semicircular arc in the studied temperature range and the centers of these semicircles lie below the real axis,which indicates that the material is an on-Debye type.These semicircular arcs are related to the bulk and the grain boundary effects.Furthermore,the alternating current conductivity of[N(C_(3)H_(7))_(4)]_(2)ZnBr_(4)obeyed Jonscher’s law:σ_(AC)(ω)=σ_(dc)+Aω^(s) and the conduction could be attributed to the correlated barrier hopping(CBH)model in both region(I)and(II)and the Non-overlapping Small Polaron Tunneling(NSPT)in region(III).
