THERMAL DIFFUSIVITY OF Bi₂Sr₂CaCu₂O₈ CERAMICS WITH NANO Ag ADDITION MEASURED USING OPEN-CELL PHOTOACOUSTIC TECHNIQUE

Abstract

This paper reports the results of thermal diffusivity measurement on nano Ag added Bi 2 Sr 2 CaCu 2 O 8- Ag x (with x = 0–1.0) ceramics using an open-cell photoacoustic instrument. The thermal diffusivities were obtained by analyzing the phase of the photo-acoustic signal of thermally thick samples using Calderon's method as well as the analysis of the phase in thermally thick region. We found that the thermal diffusivity increases with the amounts of nano Ag . The values of thermal diffusivity obtained were between 0.01250 ± 0.00128 to 0.01606 ± 0.00230 cm 2/ s for Ag 0 to Ag 1.0. The electrical resistance versus temperature measurements showed a metal-like behavior for all samples. However, a metal-like transition was observed between x = 0.5 and 0.7 when results of thermal diffusivity and electrical resistance measurements were analyzed together with samples x ≥ 0.7 showing the metallic behavior.

Thermal Diffusivity and Conductivity of La_0.7Ca_0.3-<i>x</i>Sr_<i>x</i>MnO₃ (<i>x</i>=0 to 0.10)

“…Thermal diffusivity at room was measured using open-cell photoacoustic (PA) techniques [10]. The method of analyzing the PA amplitude is best applied to PA signal with both thermoelastic bending and thermal diffusion as the dominant mechanisms, which is true for very thin samples [11,12].…”

“…Two methods of analyzing the PA phase; the Calderon's method and the analysis of phase in thermally thick region were used in this study. The details of this method has been described elsewhere [10].…”