Exercises
109
M(LiCF 3 SO 3 ) = 156 g mol
−1
Density of P(EO) 36 -LiCF 3 SO 3 = 1.3 g cm
−3
Exercise 3.7 – Electrical conductivity as a function of composition
in (CeO 2 ) 1−x (YO 1.5 ) x
Table 27 presents the experimental results for electronic conductivity σ e of the
solid solution (CeO 2 ) 1−x (YO 1.5 ) x measured at 793 °C under an oxygen partial
pressure of 1.5 # 10
−13
bar and as a function of doping level x.
Table 27 – Electronic conductivity of solid solution
(CeO 2 ) 1−x (YO 1.5 ) x as a function of doping level.
Doping level x
1.5 # 10
−1
10
−1
10
−2
10
−3
5 # 10
−4
σ e [S cm
−1
]
3.95 # 10
−3
4.85 # 10
−3
1.26 # 10
−2
3.42 # 10
−2
4.63 # 10
−2
1. Draw the curve for the function σ e = f (x) in logarithmic coordinates.
2. Derive the relation log σ e = a log x + b where a and b are constants to be
determined.
3. The dominant disorder in CeO 2 is Frenkel anionic disorder. In the solid
solution (CeO 2 ) 1−x (YO 1.5 ) x , the yttrium substitutes for cerium. Given that
2 the dominant electronic conductivity is n type,
2 the electronic mobility is constant, and
2 the species responsible for the ionic conduction is the oxide ion by a
vacancy mechanism,
establish the theoretical equation for the electronic conductivity as a function
of doping level x.
Exercise 3.8 – Conductivity of nickel oxide
At high oxygen partial pressure, nickel oxide NiO is a p-type semiconductor.
The total electrical conductivity of NiO for various oxygen partial pressures is
given in table 28 for a temperature of 1 000 °C.
Element
H
C
O
Molar mass [g mol
−1
]
1
12 16