Platinum Metals Review last published a table of the properties of the six platinum metals in October 1963. This revised table includes some more recently determined values and is expressed in SI units where appropriate.
|
Platinum |
Iridium |
Osmium |
Palladium |
Rhodium |
Ruthenium |
Atomic number |
78 |
77 |
76 |
46 |
45 |
44 |
Atomic weight |
195.09 |
192.22 |
190.2 |
106.4 |
102.9055 |
101.07 |
Thermal neutron cross section, barns |
9±1 |
425±15 |
15.3±0.7 |
6.0±1.0 |
150±5 |
3.0±0.8 |
Lattice structure |
F.c.c. |
F.c.c. |
C.p.h. |
F.c.c. |
F.c.c. |
C.p.h. |
Lattice constants at 20°C, Å a |
3.9229 |
3.8392 |
2.7340 |
3.8906 |
3.8029 |
2.7056 |
c/a |
|
|
1.5799 |
|
|
1.5825 |
Density at 20°C, kg/m3 |
21450 |
22650 |
22610 |
12020 |
12410 |
12450 |
Melting point, °C |
1768 |
2443 |
3050 |
1552 |
1960 |
2310 |
Thermal conductivity at 0−100°C, W/mK |
73 |
148 |
87 |
76 |
150 |
105 |
Specific heat at 0°C, J/kg K |
131.2 |
128.4 |
129.3 |
244.3 |
246.4 |
230.5 |
Coefficient of linear expansion at 20−100°C, × 106 |
9.1 |
6.8 |
6.1 |
11.1 |
8.3 |
9.1 |
Vapour pressure at 1500°C, Torr |
10−6 |
10−8 |
10−12 |
10−2 |
10−6 |
10−5 |
Resistivity at 0°C, μ ohm.cm |
9.85 |
4.71 |
8.12 |
9.93 |
4.33 |
6.80 |
Temperature coefficient of resistance at 0−100°C |
0.0039 |
0.0043 |
0.0042 |
0.0038 |
0.0046 |
0.0042 |
Thermal e.m.f. against platinum at 1000°C, mV |
|
+ 12.73 |
|
−11.505 |
+ 14.05 |
+9.760 |
Mass susceptibility χ, cm3/g, × 106 |
+0.9712 |
+0.133 |
+0.052 |
+5.231 |
+0.9903 |
+0.427 |
Thermionic function, A/cm2K2 |
64 |
170 |
120 |
60 |
100 |
|
Work function φ, V |
5.27 |
5.40 |
4.8 |
4.99 |
4.90 |
> 4.54 |
Tensile strength, annealed, Ib/in2, × 103 |
18 |
160 |
|
25 |
100 |
72 |
kN/m2, × 103 |
124 |
1100 |
172 |
688 |
496 |
|
Modulus of elasticity in tension, lb/in2, × 106 |
25 |
75 |
81 |
17 |
46 |
60 |
kN/m2, × 106 |
172 |
516 |
556 |
117 |
316 |
417 |
Hardness,annealed, Hv |
40–42 |
200–240 |
300–670 |
40–42 |
100–102 |
200–350 |