Photoacoustic study of the effect of degassing temperature on thermal diffusivity of hydroxyl loaded alumina

Abstract

Articles you may be interested inThe effect of thermal treatment induced inter-diffusion at the interfaces on the charge trapping performance of HfO2/Al2O3 nanolaminate-based memory devices Network structure and thermal stability study of high temperature seal glass J. Appl. Phys.The thermal diffusivity of ␥-alumina is determined by the photoacoustic method. The method is calibrated by determining the thermal diffusivity of copper and aluminum. The effect of the chemisorbed hydroxyl groups on thermal diffusivity is studied by degassing the sample at different temperatures.

Laser-induced thermal characterization of nano Ag metal dispersed ceramic alumina matrix

“…The thermal diffusivity values evaluated for copper and aluminium are 1.18 ± 0.003 cm 2 s -1 and 0.970 ± 0.004 cm 2 s -1 respectively, which agrees well with earlier reported values [4]. Figure 1 shows the log f versus log PA amplitude plot for the pure alumina sintered at 700 0 C. By knowing the transition frequency, the thermal diffusivity value is evaluated as 0.210 ± 0.002 cm 2 s -1 .…”

“…During the last two decades, the non destructive and non intrusive laser induced photothermal methods have emerged as an effective research and analytical tool for characterizing the thermal, optical and transport properties of a variety of materials such as ceramics, liquid crystals, semiconductors etc [4][5][6][7][8]. All these photothermal methods are based on the detection, by one means or other, of a transient temperature change that characterizes the thermal waves generated in the sample due to the nonradiative deexcitation followed by an intensity modulated optical excitation.…”

Thermal characterization of doped polyaniline and its composites with CoPc

“…The measured values (0.98 cm 2 s −1 and 0.26 cm 2 s −1 , respectively, for Al and GaAs) are found to be in agreement with earlier reported values of these specimens (0.99 cm 2 s −1 and 0.26 cm 2 s −1 , respectively). 12 Thermal diffusivity value essentially determines the rate of heat diffusion through the sample and the inverse of thermal diffusivity yields a measure of the time required to establish thermal equilibrium in systems for which a transient temperature change has occurred. 6,9 Figure 2 shows the phase spectrum of all the specimens under investigation.…”

Thermal characterisation of dye-intercalated K-10 montmorillonite ceramics using photoacoustic technique

“…À3/2 when 5 l by changing the chopping frequency [10,12]. The theoretical background for the evaluation of the TD from the PAS amplitude spectrum is explained elsewhere [38,39]. Since thermal diffusion length is a function of chopping frequency, the PA amplitude spectrum has a slope change at the characteristic frequency, f c , depending on sample thickness, where f c is defined by ¼ l 2 f c .…”

“…Since thermal diffusion length is a function of chopping frequency, the PA amplitude spectrum has a slope change at the characteristic frequency, f c , depending on sample thickness, where f c is defined by ¼ l 2 f c . A slope change occurs at f c in the log(amplitude) versus log(frequency) plot and knowing the sample thickness, l, the TD can be obtained using the above expression [9,11,38,39].…”