NIST Structural Ceramics Database (SCD) Database

NIST Standard Reference Database 30

Last Update to Data Content: 2002

DOI: http://dx.doi.org/10.18434/T4F30D


SCD Citation Number: Z00788

Bibliographic Information

Reference:
"The Heat Capacities of Quartz, Cristobalite and Tridymite at Low Temperatures," C. T. Anderson, Journal of the American Chemical Society, Vol. 58, pp. 568-570 (1936), published by American Chemical Society.
Language: English

General Materials Processing Notes

The sample of quartz was obtained from Utah, through the Bureau of Mines Intermountain Experiment Station at Salt Lake. It was crushed and screened to pass a 28-mesh and remain on a 35-mesh screen. It was washed with hydrochloric and nitric acids, with water and dried. An analysis of the quartz, by decomposition with hydrofluoric acid gave the impurities as 0.07%, indicating that the quartz had a purity of at least 99.93% SiO2. Its density was found to be 2.6378 g/cm3 at 22.2 °C. The calorimeter was filled with 164.9 g. The starting material for the samples of cristobalite and tridymite was a very pure sample of vein quartz from Lake Toxaway, North Carolina. The sample was ground to pass through a 60-mesh screen, repeatedly washed with hydrochloric acid and then dried. Analysis of the silica with hydrofluoric acid showed 99.99% SiO2. The residue, when tested with sodium thiocyanate, showed a red coloration indicating the presence of iron. ... the sample of cristobalite was prepared by placing the quartz in a platinum cone set into a magnesia block into which a Pt-Pt + Rh thermocouple had been inserted. The cone was covered with platinum foil resting on two porcelain rods. The assembly was placed inside a graphite tube, heated by an induction furnace for ninety minutes at 1600 °C. After cooling in the furnace it was removed. An analysis showed 99.99% SiO2, the residue again showing iron. ... It had a density of 2.3201 g/cm3 at 23.3 °C. A 98.9 g sample was studied. The preparation of the tridymite was more difficult as it was necessary to use a flux. The purified quartz was mixed with carefully purified sodium tungstate in the proportion of 6 SiO2 to 1 Na2WO4, by weight. The mixture was ground in an agate mortar to pass a 200-mesh screen, placed in the platinum cone, described above, and heated in a high temperature furnace, provided with silicon carbide heating elements, for twenty-four hours at 1250 °C. ... Analysis of the sample showed 98.7% SiO2, the remainder Na2WO4. ... the sample was reground in an agate mortar to pass through a 400-mesh screen. After screening it was ground for ten minutes longer. ... this sample showed 99.46% SiO2. 107.8 g of this sample was used in the specific heat measurements. Its density was 2.2777 g/cm3 at 23.7 °C. The average deviation from the mean of the densities in six determinations each of all three materials was ±0.0001 g/cm3."

Measurement Methods

Calorimetry
The authors cite C.T. Anderson, Journal of the American Chemical Society, Vol. 52, 2296, 2712 (1930), Vol. 54, 107 (1932), Vol. 55, 3621 (1933).

Index of Materials and Properties

Material Number 1: SiO2

Material Specification and Properties for SiO2

Material number 1 of 1
in SCD Citation Number: Z00788
Chemical Class: Oxide
Chemical Family: Si-O
Formula: SiO2
Informal Name: silica
Structure Type: Polycrystalline
Manufacturer: In-House
Process: Solid State Reaction

SiO2

Material number 1 of 1
in SCD Citation Number: Z00788
Specific Heat
Phase
 
 
Temperature
 
( K )
Molar Heat
Capacity
( J mol-1 K-1 )
Specific
Heat
( J kg-1 K-1 )
Quartz 53.4 6.481 107.9
Quartz 56.4 7.046 117.3
Quartz 60.3 7.757 129.2
Quartz 65.4 8.812 146.7
Quartz 72.8 10.47 174.3
Quartz 80.0 11.97 199.3
Quartz 87.5 13.25 220.7
Quartz 98.9 15.40 256.4
Quartz 107.9 16.84 280.5
Quartz 122.1 19.92 331.7
Quartz 134.1 22.26 370.7
Quartz 143.8 24.02 399.9
Quartz 156.2 26.07 434.1
Quartz 169.1 28.18 469.3
Quartz 184.8 30.67 510.6
Quartz 197.7 32.45 540.2
Quartz 216.1 34.97 582.2
Quartz 234.7 37.55 625.2
Quartz 252.1 39.74 661.7
Quartz 272.0 42.59 709.2
Quartz 285.0 43.14 718.2
Quartz 296.1 44.27 737.0
Cristobalite 54.8 7.276 121.1
Cristobalite 57.8 7.791 129.7
Cristobalite 61.3 8.364 139.3
Cristobalite 69.9 10.14 168.9
Cristobalite 73.7 10.97 182.7
Cristobalite 77.7 11.85 197.3
Cristobalite 83.9 12.86 214.1
Cristobalite 88.0 13.51 224.9
Cristobalite 99.8 15.88 264.4
Cristobalite 112.0 18.21 303.2
Cristobalite 120.4 17.05 283.9
Cristobalite 136.8 22.79 379.5
Cristobalite 150.7 25.33 421.7
Cristobalite 164.0 27.41 456.4
Cristobalite 178.2 29.70 494.5
Cristobalite 193.7 31.89 531.0
Cristobalite 210.9 34.40 572.7
Cristobalite 229.5 37.03 616.5
Cristobalite 241.4 38.41 639.6
Cristobalite 257.1 40.15 668.5
Cristobalite 272.2 41.72 694.6
Cristobalite 297.2 44.10 734.3
Cristobalite 297.3 44.43 739.8
Tridymite 54.2 7.364 122.6
Tridymite 57.6 7.962 132.6
Tridymite 61.5 8.581 142.9
Tridymite 68.6 10.05 167.4
Tridymite 80.5 12.62 210.2
Tridymite 90.8 14.34 238.8
Tridymite 100.4 16.48 274.5
Tridymite 108.8 17.95 298.9
Tridymite 117.7 19.58 326.0
Tridymite 131.4 22.19 369.5
Tridymite 149.3 25.38 422.5
Tridymite 164.3 27.94 465.3
Tridymite 181.6 30.64 510.1
Tridymite 187.9 31.60 526.2
Tridymite 202.6 33.63 560.0
Tridymite 219.5 35.90 597.8
Tridymite 235.4 38.05 633.5
Tridymite 249.1 39.66 660.3
Tridymite 271.8 42.17 702.2
Tridymite 278.1 42.80 712.7
Tridymite 290.8 44.14 735.0
Tridymite 294.9 44.43 739.8

Measurement Method: Calorimetry
Evaluation Status: Qualified by acceptance criteria