Microstructure of AgI–Ag2O–B2O3 fast ion conducting glasses with large amounts of AgI

Structural investigation of superionic AgI-containing orthoborate glasses

“…85 cm À1 arising from Ag-iodide sites with coordination numbers larger than four [27]. Our far infrared findings are in line with results of field-emission type scanning electron microscopy which revealed the presence of amorphous AgI particles of size 40-60 nm in diameter for x = 0.75 [10], and of Xray diffraction measurements which evidenced the formation of a-AgI particles in the range 0.8 6 x 6 0.82 and b-AgI particles for compositions x P 0.82 [7,10,11].…”

“…The presence of the aAgI phase in these materials is associated with their high ionic conductivity which can reach values as large as 10 À1 S cm À1 at room temperature [12]. X-ray diffraction measurements revealed also the formation of b-AgI particles for compositions x P 0.82, while for x < 0.8 the halo patterns indicated the amorphous nature of the materials [10]. However, fine amorphous particles of 40-60 nm in diameter were observed for the x = 0.75 composition by using field-emission type scanning electron microscopy, and were considered to be an amorphous phase rich in AgI [10].…”

“…As shown by X-ray diffraction measurements [7,10,11] the a-AgI phase can be stabilized in the composite system xAgI-(1 À x)[0.75Ag 2 O-0.25B 2 O 3 ] when 0.80 6 x 6 0.82 and the material is prepared by twinroller-assisted rapid quenching. The presence of the aAgI phase in these materials is associated with their high ionic conductivity which can reach values as large as 10 À1 S cm À1 at room temperature [12].…”

“…While previous studies were focused mainly on the state of AgI in these systems, no detailed information is available on the nature of the boron-oxygen part of the structure that hosts AgI and provides the mechanism for stabilizing the a-AgI phase in the composite materials [7][8][9][10][11]. To confirm the stabilizing mechanism of a-AgI phase, we present in this work a structural investigation of twin-roller quenched thin flakes of composition xAgI-(1 À x)[0.75Ag 2 O-0.25B 2 O 3 ] for AgI contents in the range 0.60 6 x 6 0.90.…”

Shallow‐ and deep‐luminescence centers in AgI‐based superionic conductor glass

“…1, under rapid cooling condition, glass predominantly showing the XRD pattern of αAgI phase (Type-α glass) was obtained, while under less rapid cooling condition, glass predominantly exhibiting the XRD pattern of low-temperature AgI phases (Type-β glass) was obtained. It has been elsewhere reported that AgI precipitated in glass are particles whose sizes are several ten nanometers [8]. Figure 2 shows the PL and PLE spectra of the type-α glass at 9 K. The spectra are normalized in intensity.…”