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: Z00032

Bibliographic Information

Reference:
"Thermal Expansion of Chemically Vapor-Deposited Si3N4," K. Niihara and T. Hirai, Journal of the Ceramic Society of Japan, Vol. 94 [1], pp. 146-148 (1986), published by Ceramic Society of Japan.
Language: English
Notes: Yogyo Kyokaishi

General Materials Processing Notes

The authors cite K. Niihara et al., J. Mater. Sci., Vol. 11, 593-603 (1976), and summarize the procedure as follows. "CVD-Si3N4 plates up to 2.5 mm thick were deposited on a directly heated graphite substrate using a mixture of NH3 and H2-carried SiCl4. The preparation conditions were as follows: the deposition temperature (Tdep), 1200 °C to 1400 °C; the total gas pressure (P<tot), (1.3 kPa to 10.7 kPa = 10-80 torr), the flow rates of NH3, SiCl4 (in liquid) and H2, 60 cm3/min, 0.8 cm3/min, and 700 cm3/min, respectively. The crystalline CVD-Si3N4 deposited were only α-Si3N4 and free from β-Si3N4, free silicon, and other silicon compounds. The density was 99% to 100% of theoretical density."

Measurement Methods

X-ray diffraction
"The coefficient of thermal expansion was...obtained from X-ray powder diffraction measurements of the lattice parameters, a and c, as a function of temperature. The X-ray measurements were made in a vacuum on a high-temperature diffractometer using Ni-filtered CuKα radiation from a high intensity generator (60 kV and 200 mA). The diffraction angle (2θ) was varied continuously in the range of 18° to 70°. The sample stage was made of a platinum plate, which was used as the internal standard. A suspension of crushed CVD-Si3N4 powder (<200 mesh) in acetone was applied to the sample stage, leaving a fine uniform layer of powder on the stage after evaporating acetone in a vacuum. The samples were heated by flowing electric current into the sample stage."

Index of Materials and Properties

Material Number 1: Si3N4

Material Specification and Properties for Si3N4

Material number 1 of 1
in SCD Citation Number: Z00032
Chemical Class: Nitride
Chemical Family: Si-N
Formula: Si3N4
Informal Name: silicon nitride
Structure Type: Polycrystalline
Manufacturer: In-House
Process: Chemical Vapor Deposition

Si3N4

Material number 1 of 1
in SCD Citation Number: Z00032
Elemental Composition
Amount of
Element
( formula units )
Element
 
( no unit )
3 Si
4 N

Measurement Method: Reported Formula
Evaluation Status: Unevaluated

Si3N4

Material number 1 of 1
in SCD Citation Number: Z00032
Density (mass)
Density
 
( g cm-3 )
3.17 ± 0.005

Measurement Method: Unknown
Evaluation Status: Unevaluated
Cautions:
No measurement details were noted.

Si3N4

Material number 1 of 1
in SCD Citation Number: Z00032
Thermal Expansion
Crystal
Axis
 
Temperature
Range
( °C )
Thermal
Expansion
( 10-6 K-1 )
a 20-1000 2.82
c 20-1000 3.12
average 20-1000 2.92 ± 0.17

Measurement Method: X-ray diffraction
Evaluation Status: Evaluated by acceptance criteria