Tungsten (W)
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Table 2024a. Properties of tungsten (W) .

Resistivity (10-6 Ω•cm)
5.65
Corrosion in air
Good
Melting point (°C)
3387
Specific heat capacity(Jkg-1K-1)
138
Thermal conductivity (Wcm-1)
1.74
Adhesion to SiO2
Poor
Thermal stress per degree for
films on silicon (107 dyn cm-2 °C-1)
0.8
Youngs modulus
(10-11 dyn cm-2)
41.1
Coefficient of thermal expansion (CTE) (10-6 °C-1)
4.5
  Density (g-cm-3)
19.3
Heat conductivity (kh,Wcm-1K-1)
1.67
  Melt heat (Qm, J-g-1)
193
Vaporization temperature (Tv, °C)
5930
  Vaporization heat (Qv, J-g-1)
3980
Absorption (1-R)
0.41 for 1 µm light

Table 2024b. Properties of tungsten-X chemical components.

System Lattice constant (Å) Crystal structure Space groups
W a = 3.16523 BCC Im-3m (229)
BaxWO3 (0<x<0.13)
a = 12.15, c = 3.84    
H0.09WO3
a = 5.228, c = 3.881 Tetragonal  
H0.10WO3
a = 7.247, b = 7.502, c = 3.844 Orthorhombic  
KxWO3 (0.475<x<0.57)
a = 12.3, c = 3.84    
NaxWO3 (0.28<x<0.38)
a = 12.1, c = 3.75    
(NH4)0.30WO3
a = 7.376, c = 7.575 Hexagonal  
PbxWO3 (0.17<x<0.35)
a = 12.2, c = 3.78    
SrxWO3 (0<x<0.2)
a = 12.15, c = 3.77
   

As listed in Table 2024c, substances with large bonding energies usually have high melting temperatures.

Table 2024c. Bonding energies and melting temperatures of metallic substances.

Bonding type

Substance
Bonding energy
Melting point (°C)
kJ/mol kcal/mol eV/Atom, Ion, or Molecule
Metallic
Typical value 50-1000      
Hg 68 16 0.7 -39
Al 324 77 3.4 660
Fe 406 97 4.2 1538
W 849 203 8.8 3410

Table 2024d. Reflection angles (°) for tungsten (W, a = 3.16523 Å) (λ = 1.5405929 Å and T = 298 K).

hkl Reflection angles (°)
110 40.262
200 58.251
211 73.184
220 86.996
310 100.632
222 114.923
321 131.171
400 153.535

Figure 2024 shows the solubility for impurities (including W) in SiC.

Solubility for impurities in SiC

Figure 2024. Solubility for impurities in SiC.

 

 

 

 

 

 

 

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