Growth of nanocrystalline PbS within a glass

Nanocrystalline PbS has been grown within a phase-separated oxide glass of composition 10 Na₂O, 15 PbO, 17 CaO, 3 Bi₂O₃, and 55 SiO₂ (in mole %) by passing H₂S gas over it at temperatures varying from 773 to 943 K. The particle size ranged from 2.5 to 12.9 nm. The dc resistivity of composites of nanocrystalline PbS and the phase separated glass has been measured over the temperature range 300 to 670 K. The resistivity variation in the temperature range 550 to 670 K is characterized by the sodium ion migration in the glass with an activation energy, ∼1.2 eV. The resistivity in the range 300 to 500 K was controlled by conduction in PbS particles with the estimated band gap showing an increase with a decrease in the particle size.