Carrier Type Reversal in Pb sub x Ge sub 42-x Se58 and Pb20Ge sub y Se sub 80-y Glasses Exhibited in Thermal Diffusivity Measurements
Abstract
Bulk Pb(x)Ge(42-x)Se(58)(x=0, 2.5, 5,7.5, 9, 10 &15 at.%) and Pb(20)Ge(y)Se(80-y) (y= 17, 19, 21, 23 and 25 at.%) homogeneous glasses have been prepared by melt quenching. The thermal diffusivity has been measured by the photoacoustic technique using a laboratory built non-resonant photoacoustic cell. The composition dependence of thermal diffusivity shows an anomalous behavior at x=9 at% of Pb in Pb(x)Ge(42-x)Se(58) and y=21 at% of Ge in Pb(20)Ge(y)Se(80-y)glasses, the composition at which a p-to n- conduction transition generally occurs. The reported electrical conductivity and optical band gap measurements are used to explain the minimum thermal diffusivity value obtained at the transition threshold in these glasses. These results have been explained with the Kolobov model on the basis of modification of the charged defect states due to the addition of metallic elements.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2001
- Accession Number
- ADP011544
Entities
People
- B. Thangaraju
- E. S. Gopal
- K. S. Sangunni
- Rajesh Ganesan
Organizations
- Indian Institute of Science, Bengaluru