Evaluation of the Validity of Crystallization Temperature Measurements Using Thermography with Different Sample Configurations

We describe further progress of a previously reported novel crystallization temperature ($T_{\text{x}}$) measurement method applicable for small sample sizes. The method uses thermography and detects $T_{\text{x}}$ as a change in emissivity of thin film amorphous alloy samples. We applied this metho...

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Bibliographic Details
Published inJapanese Journal of Applied Physics Vol. 49; no. 7; pp. 076601 - 076601-7
Main Authors Aono, Yuko, Sakurai, Junpei, Shimokohbe, Akira, Hata, Seiichi
Format Journal Article
LanguageEnglish
Published The Japan Society of Applied Physics 01.07.2010
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Summary:We describe further progress of a previously reported novel crystallization temperature ($T_{\text{x}}$) measurement method applicable for small sample sizes. The method uses thermography and detects $T_{\text{x}}$ as a change in emissivity of thin film amorphous alloy samples. We applied this method to various sample configurations of Pd--Cu--Si thin film metallic glass (TFMG). The validity of the detected $T_{\text{x}}$ was determined by electrical resistivity monitoring and differential scanning calorimetry (DSC). Crystallization temperature can be detected in all sample configurations; however, it was found that the magnitude of the detected change of emissivity at $T_{\text{x}}$ depended on the sample configuration. This emissivity change was clear in the absence of a higher emissivity material. The results suggest that this method can achieve high-throughput characterization of $T_{\text{x}}$ for integrated small samples such as in a thin film library.
Bibliography:(Color online) $T$--$T_{\text{a}}$ curve showing emissivity change for the case of (a) emissivity increasing and (b) emissivity decreasing. (Color online) Schematic diagram of experimental setup for heating test. (Color online) Larger-sized sample used to verify the measurement technique: (a) photograph of sample separated into two pieces, each $7 \times 16$ mm 2 with a thickness of 4 \mbox{$\mu$m}; (b) schematic illustration of setup for heating test. A current of 0.1 A was applied to one sample using a constant current source. The apparent temperature, $T_{\text{a}}$, was measured as the average value over the hatched area and the emissivities shown in Fig. were measured at point A and B (on sample and on alumina, respectively). (Color online) $T$--$T_{\text{a}}$ curve, electrical resistivity and DSC data for larger-sized ($7 \times 16$) sample. (Color online) Change in emissivity with temperature for larger-sized sample. The sample and alumina measurement points are indicated in Fig. ; (a) apparent emissivity, (b) emissivity relative to the value at 550 K ($T_{\text{x}} = 657$ K is obtained from the DSC results shown in Fig. ). (Color online) XRD patterns of as-sputtered and post-heating samples. (Color online) Conventional thin film library size sample: (a) fabrication method; (b) photograph of finished sample chip. (Color online) $T$--$T_{\text{a}}$ curve of thin film library size ($1 \times 1$ mm 2 ) sample ($T_{\text{x}} = 657$ K is obtained from the DSC results shown in Fig. ). (Color online) Change in emissivity with temperature for thin film library size sample: (a) apparent emissivity; (b) emissivity relative to the value at 550 K ($T_{\text{x}} = 657$ K is obtained from the DSC results shown in Fig. ). (Color online) Schematic illustration of infrared radiation from alumina and TFMG. (Color online) Effect of alumina on the larger-sized sample: (a) schematic illustration defining the position $x$ measured from the sample; (b) emissivity as a function of $x$ (left axis) at 630 K (square symbols) and 670 K (round symbols). The triangular symbols indicate the percentage change in emissivity (right axis) from 630 to 670 K. (Color online) Dependence of $T$--$T_{\text{a}}$ curve shape on position $x$ within the sample ($T_{\text{x}} = 657$ K is obtained from the DSC results shown in Fig. ). (Color online) Dependence of two defined $T_{\text{x}}$s in Fig. on position $x$ within the sample ($T_{\text{x}} = 657$ K is obtained from the DSC results shown in Fig. ). (Color online) $T$--$T_{\text{a}}$ curve of resized sample ($T_{\text{x}} = 657$ K is obtained from the DSC results shown in Fig. ). (Color online) Schematic cross section of sample on metal chip. (Color online) Fabrication method of sample with groove chip. (Color online) $T$--$T_{\text{a}}$ curves for metal covered samples ($T_{\text{x}} = 657$ K is obtained from the DSC results shown in Fig. ). (Color online) $T_{\text{x}}$ distribution for different sample configurations and definitions of $T_{\text{x}}$ ($T_{\text{x}} = 657$ K is obtained from the DSC results shown in Fig. ).
ISSN:0021-4922
1347-4065
DOI:10.1143/JJAP.49.076601