Structural and physical properties of Fe 2 O 3 -doped lead vanadate glass
- PDF / 273,242 Bytes
- 4 Pages / 612 x 792 pts (letter) Page_size
- 22 Downloads / 180 Views
MATERIALS RESEARCH
Welcome
Comments
Help
Structural and physical properties of Fe2O3-doped lead vanadate glass S. Mandala) and S. Hazrab) Department of Solid State Physics, Indian Association for the Cultivation of Science, Jadavpur, Calcutta 700032, India
(Received 24 February 1998; accepted 15 October 1999)
The role of Fe2O3 in the structural and physical properties of ternary lead vanadium iron glass system has been studied in comparison with the binary lead vanadate glasses. X-ray diffraction, scanning electron microscopy, and differential thermal analysis show that homogeneous glasses of composition 10Fe2O3 ⭈ xV2O5 ⭈ (90 − x)PbO can be obtained for x ⳱ 50 to 80 mol%. Observation from the infrared spectroscopy shows that the basic building blocks of these glasses are same as those of crystalline V2O5, while differential thermal analysis and electrical conduction of these glasses suggest that there is a strong role of iron, both in the glass network and in the conduction mechanism for the glasses containing a low percentage of vanadium.
I. INTRODUCTION
II. EXPERIMENT
Oxide glasses containing transition metal ions are of great interest because of their possible application in the field of optical switching and memory switching devices.1,2 They show semiconducting properties due to the presence of two different valence states of the transition metal ions. Glasses containing vanadium are of particular interest since vanadium itself forms the glassy network and hence a large amount of vanadium can be incorporated. The glasses containing vanadium are highly conductive, which makes them more suitable for applications in electrical switching devices. Some work on the vanadate glasses has been done recently3–5 in which vanadium oxide plays the unique role of network former. Recently, we have studied some structural5 and electrical properties6 of the lead vanadate glass system. In the present work, iron oxide was used to dope the lead vanadate glasses in a fixed proportion, and the role of iron on the structural and electrical properties of the prepared glass samples was studied in comparison with the lead vanadium glasses with the change of glass composition. It was attempted to correlate the results from the structural studies with the results of the electrical studies.
Glass samples of compositions 10Fe2O3 ⭈ xV2O5 ⭈ (90 − x)PbO with x ⳱ 50 to 80 mol% have been prepared from reagent grade chemicals V2O5, PbO, and Fe2O3. The chemicals mixed in desired proportions were melted in pure alumina crucibles. The melts were kept for 1 h in the temperature range 900–1000 °C depending on the glass composition for homogeneous mixing. The vitrification was achieved by subsequent rapid cooling of the melts between two brass plates. Chemical analyses were done to find out any trace of aluminum in the glass samples. The results, however, were negative. The x-ray diffraction patterns of the as-prepared and of the heat-treated samples were taken in a Philips x-ray diffractometer (model PW 1050/51). The scanning electron micros
Data Loading...
