ISSN:
1573-8663
Keywords:
Mn-doped BaTiO3
;
electrical conductivity
;
thermopower
;
defect structure
Source:
Springer Online Journal Archives 1860-2000
Topics:
Electrical Engineering, Measurement and Control Technology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The electrical conductivity and thermoelectric power of Mn-doped BaTiO3 (1 mole%) and “undoped” BaTiO3 have been measured as functions of oxygen partial pressure (in the range of 10-16 to 1 atm) and temperatures (in the range of 900 to 1200°C), and compared with each other to differentiate the effect of the Mn-addition. It is found that the isothermal conductivity of Mn-doped BaTiO3 varies with increasing Po2 as σ ∝ $$Po_2^{ - 1/4} $$ to ∝ $${\text{Po}}_2^{ - 1/6} $$ to ∝ $${\text{Po}}_2^{ + 1/6} $$ , unlike previously reported. This behavior is well explained by the shift of the ionization equilibrium, $${\text{Mn}}_{Ti}^x $$ . The corresponding equilibrium constant, KA, is determined from the Po2 values demarcating those three different Po2 regions as $$K_A /{\text{cm}}^{ - 3} $$ =3.19×1022 exp(−1.69 eV/kT). Basic parameters involving carrier density and mobility, and defect structure of Mn-doped BaTiO3 are discussed in comparison with those of undoped BaTiO3.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1009994230779
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