Difference between revisions of "Hot Gas Blower (Cyberstar)"
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delta(c)/c (%) = -0.192 + (5.927E-4 * T) + (2.142E-7 * T^2) - (2.207E-11 * T^3) (T/K) | delta(c)/c (%) = -0.192 + (5.927E-4 * T) + (2.142E-7 * T^2) - (2.207E-11 * T^3) (T/K) | ||
assuming a room-temperature lattice parameter of ''c'' = 12.9934 A | assuming a room-temperature lattice parameter of ''c'' = 12.9934 A | ||
Finally, plotting observed vs nominal set temperatures for the Al2O3 data gives a correction curve and equation for other hot air blower under similar measurement conditions. | Finally, plotting observed vs nominal set temperatures for the Al2O3 data gives a correction curve and equation for other hot air blower under similar measurement conditions. | ||
These results (from July 2012) are | These results (from July 2012) are shown below. These calibration data are kindly shared by Jae-Hyuk Her, GE Global Research. | ||
'''Reference 1''' = J. Appl. Cryst. (1993). 26, 77-81 | |||
=== Phase Transitions === | === Phase Transitions === | ||
Revision as of 22:38, 24 September 2012
About
11-BM has a dedicated Cyberstar Hot Gas Blower. This can be used to heat small diameter capillary samples from ambient temperature to ~ 950 °C
About
Temperature Range and Ramp Rate.
- ambient temperature to ~ 950 °C
- Max ramp rate on heating & cooling is 5 deg C/min (300 C/hour)
Users should plan experiments to incorporate these heating and cooling ramp times.
11-BM Hot Gas Blower Image
Temperature Profile & Alignment
Temperature Calibration
Al2O3 Thermal Expansion
In-situ calibration of the hot gas blower was performed using the known thermal expansion of Al2O3 alumina a & c unit cell parameters as a function of temperature.
Full powder diffraction patterns were collected for select "nominal" set temperatures between 100 - 950 C at 11-BM using a X.X mm diameter fused quartz capillary load with ??? Al2O3 powder.
Refinements were performed against data from each nominal temperature to determine a & c unit cell parameters.
Based on the initial room temperature 25 C lattice values and published thermal expansion equations (below, see Reference 1), "real" observed sample temperatures were then calculated independently for each set of 'a & c unit cell terms.
The thermal expansion equation used for the a axis of Al203 (range 293-1900 K) is:
delta(a)/a (%) = -0.176 + (5.431E-4 * T) + (2.150-7 * T^2) - (2.810E-11 * T^3) (T/K) assuming a room-temperature lattice parameter of a = 4.7592 A
The thermal expansion equation used for the c axis of Al203 (range 293-1900 K) is:
delta(c)/c (%) = -0.192 + (5.927E-4 * T) + (2.142E-7 * T^2) - (2.207E-11 * T^3) (T/K) assuming a room-temperature lattice parameter of c = 12.9934 A
Finally, plotting observed vs nominal set temperatures for the Al2O3 data gives a correction curve and equation for other hot air blower under similar measurement conditions.
These results (from July 2012) are shown below. These calibration data are kindly shared by Jae-Hyuk Her, GE Global Research.
Reference 1 = J. Appl. Cryst. (1993). 26, 77-81
Phase Transitions
SiO2
PbTiO3
