NASICON-type structure lithium ion conductors have been considered as promising solid electrolytes due to its very high Li + -ion conductivity and chemical stability. In this paper, NASICON-type structured Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 (LAGP) glass–ceramics are prepared from crystallization of glass powders, which are obtained by a simple melt-quench method. NH 4 H 2 PO 4 , H 3 PO 4 , P 2 O 5 and H 3 PO 4 &Al(PO 3 ) 3 are used as phosphorus sources, respectively. The obtained LAGP glass–ceramics are systematically characterized with X-ray diffraction, field emission scanning electron microscopy , differential scanning calorimetry and AC impedance spectroscopy . The different impurities are formed depending on the phosphorus sources, which further influence the microstructure. As a result, the lithium ion conductivity is significantly affected by the phosphorus sources. The highest conductivity of 5.21 × 10 − 4 S·cm − 1 is obtained when H 3 PO 4 is used as the phosphorus source under optimum conditions.
In this study, phosphate glasses embedded with Fe 2 O 3 quantum dots were prepared via a conventional melt quenching technology with further heat treatment. The effect of Fe 2 O 3 content on the structural, optical and magneto-optical properties was investigated. The results showed that the addition of Fe 2 O 3 had no obvious influence on the structure units that built up the host glass and the amorphous nature of glass. In the glass matrix , the existence of Fe 2 O 3 quantum dots was confirmed by high resolution transmission electron microscope . Meanwhile, optical study clearly demonstrated a red shift in optical cut-off wavelength resulted from the size quantization effect. The highest Verdet constant (22.33°/T-cm) was measured for the glass containing 1 mol% Fe 2 O 3 , which was ~ 7 times higher than that of the glass matrix. As the increment of Fe 2 O 3 contents, a phase evolution of Fe 2 O 3 quantum dots from amorphous phase to γ-Fe 2 O 3 phase was recorded due to the Ostwald Ripening effect. Interestingly, a concentration quenching phenomenon in Verdet constant was observed along with the phase evolution of Fe 2 O 3 quantum dots. When the content of Fe 2 O 3 is up to 2 mol%, the glass exhibited paramagnetism with the Verdet constant of − 2.833°/T-cm. This finding can provide a new idea for the development of quantum dot embedded magneto-optical glass.