en گروه سرامیک Ceramic Materials and Engineering Research Paper Research Paper <span style="font-size:12pt"><span style="line-height:200%"><span new="" roman="" style="font-family:" times=""><span style="font-size:10.0pt"><span style="line-height:200%"><span style="background-color:#ffffff;">The structural and electrochemical properties of Gd-doped perovskite oxides were investigated to improve the performance of solid oxide fuel cell (SOFC) cathodes. Ba</span>_{<span style="background-color:#ffffff;">0.5</span>}<span style="background-color:#ffffff;">Sr</span>_{<span style="background-color:#ffffff;">0.5-x</span>}<span style="background-color:#ffffff;">Gd</span>_{<span style="background-color:#ffffff;">x</span>}<span style="background-color:#ffffff;">CoO</span>_{<span style="background-color:#ffffff;">3-&delta;</span>}<span style="background-color:#ffffff;"> and BaSr</span>_{<span style="background-color:#ffffff;">1-x</span>}<span style="background-color:#ffffff;">Gd</span>_{<span style="background-color:#ffffff;">x</span>}<span style="background-color:#ffffff;">Co</span>_{<span style="background-color:#ffffff;">2</span>}<span style="background-color:#ffffff;">O</span>_{<span style="background-color:#ffffff;">5+&delta;</span>}<span style="background-color:#ffffff;"> (BSGC) compounds were synthesized via a </span><strong><span style="background-color:#ffffff;">sol&ndash;gel thermolysis</span></strong><span style="background-color:#ffffff;"> method to elucidate the effects of Gd incorporation on crystal structure, microstructure, and electrochemical activity. </span><strong><span style="background-color:#ffffff;">X-ray diffraction (XRD)</span></strong><b><span style="background-color:#ffffff;"> </span></b><span style="background-color:#ffffff;">and </span><strong><span style="background-color:#ffffff;">scanning electron microscopy (SEM)</span></strong><span style="background-color:#ffffff;"> confirmed the coexistence of simple and double perovskite phases, with Gd substitution leading to finer grains (down to 0.4 </span><span style="background:yellow"><span style="background-color:#ffffff;">&plusmn; 0.14</span></span><span style="background-color:#ffffff;"> &mu;m) and improved phase homogeneity. </span><strong><span style="background-color:#ffffff;">Area-specific resistance (ASR)</span></strong><span style="background-color:#ffffff;"> and conductivity measurements revealed a strong structure&ndash;performance relationship. The optimal composition, Ba</span>_{<span style="background-color:#ffffff;">0.5</span>}<span style="background-color:#ffffff;">Sr</span>_{<span style="background-color:#ffffff;">0.3</span>}<span style="background-color:#ffffff;">Gd</span>_{<span style="background-color:#ffffff;">0.2</span>}<span style="background-color:#ffffff;">CoO</span>_{<span style="background-color:#ffffff;">3-&delta;</span>}<span style="background-color:#ffffff;">, exhibited </span><span style="background:yellow"><span style="background-color:#ffffff;">an exceptionally low ASR of </span><strong><span style="background-color:#ffffff;">0.12 &Omega; cm&sup2;</span></strong><b><span style="background-color:#ffffff;"> </span></b><span style="background-color:#ffffff;">at 700 &deg;C which further decreased to a minimum of 0.04 </span><strong><span style="background-color:#ffffff;">&Omega; cm&sup2;</span></strong><span style="background-color:#ffffff;"> at 850 &deg;C, significantly</span></span><span style="background-color:#ffffff;"> outperforming GdBaCo</span>_{<span style="background-color:#ffffff;">2</span>}<span style="background-color:#ffffff;">O</span>_{<span style="background-color:#ffffff;">5+&delta;</span>}<span style="background-color:#ffffff;"> (GBCO), (1.76 &Omega; cm&sup2;). These findings demonstrate that rational structural design through rare-earth doping effectively enhances oxygen transport and electrochemical activity, providing a promising pathway for high-performance intermediate-temperature SOFC cathodes.</span></span></span></span></span></span> Ba0.5Sr0.5-xGdxCoO3-δ,BaSr1-xGdxCo2O5+δ,Electrical conductivity,Electrochemical properties,Fuel cells 0 0 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-6235-1&slc_lang=en&sid=1 Sara Tafaroji sara.tafaroji@gmail.com 1800319475328460022558 1800319475328460022558 Yes Physics Department, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, I.R. Iran Mansoor Farbod farbod_m@scu.ac.ir 1800319475328460022559 1800319475328460022559 No Physics Department, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, I.R. Iran