NIST Standard Reference Database 30
Last Update to Data Content: 2002
"Thermal Expansion of TiB2," E.C. Skaar and William J. Croft, Journal of the American Ceramic Society, Vol. 56 [1], pp. 45-45 (1973), published by American Ceramic Society.Language: English
"...TiB2 (Union Carbide Corp., New York, NY) powder in acetone was applied to the sample stage. The acetone was allowed to evaporate, leaving a fine uniform layer of powder on the stage."
The authors cite J. Intrater et al., Rev. Sci. Instrum., Vol. 32, No. 8, 905 (1961), and summarize the procedure as follows. "The X-ray measurements were made on a high-angle diffractometer using Ni-filtered Cu radiation from a high-intensity tube (40 kV and 20 mA). The diffraction angle (2ϑ) was varied continuously from 20° to 122°. Divergence angles of 1° and 4°, respectively, were used on the low and high diffraction angles. The detector was a scintillation counter which was fed into a pulse-height analyzer. The X-ray sample was mounted under vacuum in a high-temperature camera. For low temperatures (25 °C to 800 °C), the sample stage was made of a Pt-Rh alloy, and for the higher temperatures, the Ta stage was used. The temperature was measured and controlled by a Pt - Pt13Rh thermocouple welded to the underside of the stage. A suspension of fine (<200 mesh) TiB2 powder in acetone was applied to the sample stage. The acetone was allowed to evaporate, leaving a fine uniform layer of powder on the stage. The lattice parameters were calculated with each reflection weighted according to Hess' scheme. The Nelson-Riley function was used to allow for the effect of absorption and beam divergence. The cell size was then calculated by extrapolating 2ϑ to 180° and fitted by a least-squares method. ... No hysteresis was observed in any of the measurements."
| Temperature ( °C ) | Temperature ( K ) | Axis | Axis Length ( Å ) |
|---|---|---|---|
| 25 | 298 | a | 3.027(1) |
| 25 | 298 | c | 3.231(1) |
| Temperature ( °C ) | Temperature ( K ) | Axis | Thermal Expansion ( 10-6 K-1 ) |
|---|---|---|---|
| 25 | 298 | a | 7.30 |
| 500 | 773 | a | 7.28 |
| 1000 | 1273 | a | 7.25 |
| 25 | 298 | c | 10.27 |
| 500 | 773 | c | 10.23 |
| 1000 | 1273 | c | 10.20 |