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The present study is focused in two directions. In the first part, BaFe_{(1 − <i>x</i>) − 0.01}Al_0.01Ta_<i>x</i>O_{3 − <i>δ</i>} (BFAT<i>x</i>) thick films with a Ta content between 0.1 and 0.4 were manufactured using the novel room temperature coating method <q>aerosol deposition</q> (ADM), and its material properties were characterized to find the best composition of BFAT<i>x</i> for temperature-independent oxygen sensors. The material properties <q>Seebeck coefficient</q> and <q>conductivity</q> were determined between 600 and 800 °C at different oxygen partial pressures. BaFe_0.69Al_0.01Ta_0.3O_{3 − <i>δ</i>} (BFAT30) was found out to be very promising due to the almost temperature-independent behavior of both the conductivity and the Seebeck coefficient. In the second part of this study, films of BFAT30 were prepared on a special transducer that includes a heater, equipotential layers, and special electrode structures so that a combined direct thermoelectric/resistive oxygen sensor of BFAT30 with almost temperature-independent characteristics of both measurands, Seebeck coefficient and conductance could be realized. At high oxygen partial pressures (<i>p</i>O₂ &gt; 10⁻⁵ bar), the electrical conductance of the sensor shows an oxygen sensitivity of <i>m</i>  =  0.24 (with <i>m</i> being the slope in the log<i>σ</i> vs. log<i>p</i>O₂ representation according to the behavior of <i>σ</i><i>α</i><i>p</i>O₂^<i>m</i>), while the Seebeck coefficient changes with a slope of −38 µV K⁻¹ per decade of <i>p</i>O₂ at 700 °C. However, at low <i>p</i>O₂ (<i>p</i>O₂ &lt; 10⁻¹⁴ bar) the conductance and the Seebeck coefficient change with <i>p</i>O₂, with a slope of <i>m</i>  =  −0.23 and −21.2 µV K⁻¹ per decade <i>p</i>O₂, respectively.