Abstract Ferrite perovskite sensors based on L a 0.885 P b 0.005 C a 0.11 F e 1 - x C o x O 2.95 ( where x = 0.00 , 0.05, 0.10 and 0.15) were prepared using the sol-gel method. Structural, magnetic and gas sensing properties were investigated. The structural study shows that all samples crystallize in the orthorhombic system in the Pnma space group. Magnetization analysis based on M ( T ) curves shows the presence of a second order transition from a ferromagnetic ( F M ) to a paramagnetic ( P M ) state at the Curie temperature T C . T C decreases from 709 K to 684 K when the percentage of Co increases to 10 %. Introducing cobalt instead of iron causes a decline of the maximum magnetization, which drops from 0.90 with x = 0.00 to 0.01 with x = 0.15 . In addition, we find that an increase in Co content induces a decrease in the volume and porosity of the compounds. Increasing the concentration of Co thus decreases sensor sensitivity with respect to the gas to be detected, which in this study is ammonia, NH3. The normalized electrical sensor response decreases from 1.027 to 1.014 respectively for Co concentrations of x = 0.00 (undoped sample) and x = 0.05 with an exposure of 10 ppm of ammonia at 270 ° C . We show that L a 0.885 P b 0.005 C a 0.11 F e 1 - x C o x O 2.95 ( 0.00 ≤ x ≤ 0.15 ) -based compounds can be considered as potential candidates for ammonia detection and that in fact they are able to detect NH3 concentrations of around 10 p p m .

中文翻译：

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La0.885Pb0.005Ca0.11Fe1-xCoxO2.95(0.00≤x≤0.15)化合物结构、磁性和气敏特性的相关性

摘要 使用溶胶-凝胶法制备了基于 L a 0.885 P b 0.005 C a 0.11 F e 1 - x C ox O 2.95（其中 x = 0.00、0.05、0.10 和 0.15）的铁氧体钙钛矿传感器。研究了结构、磁性和气体传感特性。结构研究表明，所有样品均在 Pnma 空间群的正交晶系中结晶。基于 M(T) 曲线的磁化分析表明，在居里温度 TC 下存在从铁磁 (FM) 到顺磁 (PM) 状态的二阶跃迁。当 Co 的百分比增加到 10% 时，TC 从 709 K 减少到 684 K。引入钴而不是铁会导致最大磁化强度下降，从 x = 0.00 时的 0.90 下降到 x = 0.15 时的 0.01 。此外，我们发现 Co 含量的增加会导致化合物的体积和孔隙率降低。因此，增加 Co 的浓度会降低传感器对要检测的气体（在本研究中为氨，NH3）的灵敏度。对于 x = 0.00（未掺杂的样品）和 x = 0.05 的 Co 浓度，在 270°C 下暴露 10 ppm 氨时，归一化的电传感器响应分别从 1.027 降至 1.014。我们表明，基于 L a 0.885 P b 0.005 C a 0.11 F e 1 - x C ox O 2.95 ( 0.00 ≤ x ≤ 0.15 ) 的化合物可被视为氨检测的潜在候选物，事实上它们能够检测 NH3浓度约为 10 ppm。对于 x = 0.00（未掺杂样品）和 x = 0.05 的 Co 浓度，在 270°C 下暴露 10 ppm 氨时，归一化的电传感器响应分别从 1.027 降低到 1.014。我们表明，基于 L a 0.885 P b 0.005 C a 0.11 F e 1 - x C ox O 2.95 ( 0.00 ≤ x ≤ 0.15 ) 的化合物可被视为氨检测的潜在候选物，事实上它们能够检测 NH3浓度约为 10 ppm。对于 x = 0.00（未掺杂样品）和 x = 0.05 的 Co 浓度，在 270°C 下暴露 10 ppm 氨时，归一化的电传感器响应分别从 1.027 降低到 1.014。我们表明，基于 L a 0.885 P b 0.005 C a 0.11 F e 1 - x C ox O 2.95 ( 0.00 ≤ x ≤ 0.15 ) 的化合物可被视为氨检测的潜在候选物，事实上它们能够检测 NH3浓度约为 10 ppm。