Superionic behavior in the xAgI–(1−x)CsAg2I3 polycrystalline system

• Published in: The Journal of physics and chemistry of solids Vol. 93; pp. 126 - 130
• Main Authors: Rodríguez, L.A., Zapata, J., Vargas, R.A., Peña Lara, D., Diosa, J.E.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2016
• Subjects: Crystal structure; Differential scanning calorimetry (DSC); Ionic conductivity; Phase transitions; X-ray diffraction; X-ray diffraction; Differential scanning calorimetry (DSC); Phase transitions; Ionic conductivity; Crystal structure
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2016.02.018

A superionic phase behavior (with DC ionic conductivities higher than 0.01S/cm) has been observed in xAgI–(1−x)CsAg2I3 (x≈0.67) polycrystalline system grown by slow evaporation using AgI and CsI powders (molar ratio Cs/Ag=0.25) as starting salts and an aqueous solution of HI as solvent. The transition from the normal-to- the superionic state is first-order with a hysteretic behavior in temperature centered at about 116°C as reflected by thermal (DSC) and electrical conductivity measurements. This mixture is composed of CsAg2I3 and AgI crystalline phases and an additional amorphous AgI phase that explains the glassy-type behavior observed in the superionic phase transition. •The CsAg2I3–AgI binary system shows a superionic state and high-temperature phase transitions.•The ionic conductivity in the superionic state is 10−2S/cm and activation energy 0.24eV.•The electrical properties of CsAg2I3–AgI are interesting for applications in electrochemical devices.