The contribution of extrinsic skew scattering to the anomalous Nernst effect (ANE) provides a potential avenue to enhance transverse thermoelectric response through spin-dependent scattering mechanism. In this study, we show the effect of ${\mathrm{Cu}}_{95}{\mathrm{Ir}}_5$ addition on the enhancement of the anomalous Nernst thermopower $\left(S_{\mathrm{ANE}}\right)$ in a CoFe thin film. A high-throughput screening based on the lock-in-thermography method for thermal responses induced by the anomalous Ettingshausen effect (AEE), the reciprocal of ANE, across a composition-spread thin film of CoFe-${\mathrm{Cu}}_{95}{\mathrm{Ir}}_5$ identified the optimal composition for ANE. Based on this screening experiment, we fabricated the specific composition ${\left(\mathrm{CoFe}\right)}_{63}{\left({\mathrm{Cu}}_{95}{\mathrm{Ir}}_5\right)}_{37}$ film and measured the electric and thermoelectric transport properties. The $S_{\mathrm{ANE}}$ value reaches 1.23 µV/K for ${\left(\mathrm{CoFe}\right)}_{63}{\left({\mathrm{Cu}}_{95}{\mathrm{Ir}}_5\right)}_{37}$ at room temperature, which is much higher than that for CoFe as well as composition-matched references ${\left(\mathrm{CoFe}\right)}_{64.85}{\left(\mathrm{Cu}\right)}_{35.15}$ and ${\left(\mathrm{CoFe}\right)}_{98.15}{\left(\mathrm{Ir}\right)}_{1.85}$, which contain the same amount of only Cu and only Ir, respectively. The scaling analysis on the anomalous Hall effect reveals that the extrinsic skew-scattering contribution is significantly greater for the ${\left(\mathrm{CoFe}\right)}_{63}{\left({\mathrm{Cu}}_{95}{\mathrm{Ir}}_5\right)}_{37}$ film compared to others at 300 K. This enhancement in the extrinsic contribution is attributable to the cooperative role of Cu and Ir; Ir acts as a dominant source of skew scattering due to large spin-orbit interaction, while Cu modifies the scattering potential symmetry and accelerates the skew scattering. These results offer an effective strategy for boosting $S_{\mathrm{ANE}}$ and provide critical insights into extrinsic mechanisms for ANE.

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• Anomalous Hall effect
• Magnetism
• Nernst effect
• Thermoelectrics
• Thin films
• Epitaxy
• X-ray diffraction