Elameen Ashraf A A, Dawczak Arkadiusz, Miruszewski Tadeusz, Gazda Maria, Wachowski Sebastian
Department of Chemical and Physical Sciences, University of L'Aquila, L'Aquila, Italy.
Institute of Nanotechnology and Materials Engineering, Faculty of Applied Physics and Mathematics, and Advanced Materials Centre, Gdańsk University of Technology, Gdańsk, Poland.
Phys Chem Chem Phys. 2023 Nov 1;25(42):29127-29134. doi: 10.1039/d3cp01741a.
This work investigates how configurational entropy in oxides could affect proton conductivity. For this purpose, three samples of different elemental compositions are synthesized. Five, six and seven elements were introduced into the A-site of ANbO, forming La Nd SmGd EuNbO, LaNdSmGdEuHoNbO and LaNdSmGdEuHoErNbO, respectively. The high configuration disorder changes the local environment, which can have a notable effect on many properties, including proton transport, which is the focus of this work. The conductivity was measured in different atmospheres; dry and wet and in a different temperature range (600-800 °C) to compare the proton transport as well as study the effect of temperature. A homogenous single-phase monoclinic fergusonite was obtained for the three samples. Proton conductivity, measured by means of comparing the conductivity in dry and wet atmospheres, was observed in all samples. La Nd SmGd EuNbO4 exhibited the highest conductivity, about 3.0 × 10 S cm at 800 °C in the wet atmosphere, while in the dry atmosphere it was about 2.2 × 10 S cm at the same temperature, which implies a modest proton conductivity in this class of materials.
这项工作研究了氧化物中的构型熵如何影响质子传导率。为此，合成了三种不同元素组成的样品。分别向ANbO的A位引入了五种、六种和七种元素，形成了LaNdSmGdEuNbO₄、LaNdSmGdEuHoNbO₄和LaNdSmGdEuHoErNbO₄。高度的构型无序改变了局部环境，这可能对包括质子传输在内的许多性质产生显著影响，而质子传输正是本工作的重点。在不同气氛（干燥和潮湿）以及不同温度范围（600 - 800°C）下测量电导率，以比较质子传输情况并研究温度的影响。这三个样品均获得了均匀的单相单斜钛铌矿。通过比较干燥和潮湿气氛中的电导率来测量质子传导率，所有样品中均观察到了质子传导率。LaNdSmGdEuNbO₄在800°C潮湿气氛中的电导率最高，约为3.0×10⁻⁵ S/cm，而在相同温度的干燥气氛中约为2.2×10⁻⁵ S/cm，这表明这类材料中的质子传导率适中。
