Title of article :
Correction of Edge Effect in AC Calorimetric Method for Measuring Thermal Diffusivity of CVD Diamond Films1
Author/Authors :
Y. Gu، نويسنده , , F. Liao and I. Hatta ، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2000
Abstract :
In the thermal diffusivity measurement of a CVD diamond film using an ac
calorimetric method, the reflection of an ac temperature wave at the edge of the
film sample should be considered due to the limited length of the sample and
its high thermal diffusivity, i.e., the edge effect. In this case, the measured ther-
mal diffusivity is given as a function of frequency. The relation between the
measured thermal diffusivity and the frequency is represeInted as an analytical
expression. The real thermal diffusivity is obtained by correcting the edge effect
by two means. One is an iterative method using the directly measured edge
length of the sample to fit the analytical expression. The other is a parameter
estimation method by which a simplex method is used to estimate the edge
length and the real thermal diffusivity. Thermal diffusivities of two diamond
films were measured, and data were analyzed using the above methods. The
result shows that the parameter estimation method is relatively accurate and
convenient in processing test data.
Keywords :
ac calorimetric method , Edge effect , CVD diamond film , thermal diffusivity. , Parameter estimation
Journal title :
International Journal of Thermophysics
Journal title :
International Journal of Thermophysics