Composition-induced phase transition in a [Ag2HgI4:0.2AgI] mixed composite system doped with CuI

Abstract

Abstract:© Versita Sp. z o.o. A novel composite superionic system, [Ag 2 HgI 4 :0.2AgI]:xCuI, (x = 0.2, 0.4, 0.6 mol. wt.%), was prepared and [Ag 2 HgI 4 :0.2AgI] mixed system was used as the host. Electrical conductivity was measured to study the transition behavior at frequencies of 100 Hz, 120 Hz, 1 kHz, and 10 kHz in the temperature range 90° -170°C by a Gen Rad 1659 RLC Digibridge. Sharp increase in conductivity was observed for β-α phase transitions. As a result of increase in the dopant-to-host ratio, the conductivity of the system exhibited Arrhenius (thermally activated)-type behavior. X-ray powder diffraction, differential scanning calorimetry (DSC), differential thermal analysis (DTA) and thermo-gravimetric analysis (TGA) studies confirmed the doping effect on the transition in the host, the phase transition temperature increased with an increase in the dopant concentration. Activation energies for the system in eV both for the pretransition and post-transition phase transformations are reported.

Study of phase transition in a [CdHgI4 : 0.2AgI] mixed conducting composite system doped with KI and K2SO4

“…wt% then increases in the temperature range from 150 C to 170 C. Variations in the composition of the dopant in the host affected the phase change within the temperature range from 150 C to 180 C. This phenomenon is usually observed in different composite system [10][11][12]. In the log T versus x plot (Figure 2(a) and (b)), this mixed composite system looks qualitatively similar to those reported in the literature [23] but the values differ quantitatively in different temperature range [15].…”

Phase transition study in a [Cu2HgI4:0.2AgI] mixed composite system doped with K2SO4

“…In the log σT vs x plot (Fig. 2), this mixed composite system looks qualitatively similar to those reported in the literature [13] but the σ values differ quantitatively at different temperature range [19].…”

“…AgI is known as typical superionic conductors, the superionic phase of AgI appears at 420 K. The value of the ionic conductivity is as high as about 1 Ω −1 cm −1 [14]. It has been observed that a much better solid electrolyte composite system can be prepared with the host [Cu 2 HgI 4 :0.2AgI] [13].…”

“…wt.%) mixed composite solid with K 2 SO 4 as the dopant, and [Cu 2 HgI 4 :0.2AgI] as a host. The composition of the host was kept constant in all the composite samples [13]. AgI is known as typical superionic conductors, the superionic phase of AgI appears at 420 K. The value of the ionic conductivity is as high as about 1 Ω −1 cm −1 [14].…”

“…More recently, the development of a new solid electrolyte system involving AgI, CuI and CdI 2 , and oxysalts [8][9][10][11][12], and [M 2 HgI 4 :0.2AgI] (where M = Ag, Cu, and Cd) doped with CuI, KI, and K 2 SO 4 [11][12][13] was attempted by many researchers. Therefore, in the present study, the investigations are focused on an alternative novel composite compound, [Cu 2 HgI 4 :0.2AgI]:0.xK 2 SO 4 (x=0.2, 0.4, and 0.6 mol.…”