研究目的
To study the effect of A-site cation mismatch on the structural, magnetic, and transport properties of La0.7Ca0.25A0.05Mn0.8Cr0.2O3 (A = Ca, Li, Na, K) manganites.
研究成果
The study concluded that the conduction mechanism in the high temperature paramagnetic semiconducting region was dominated by the small polaron hopping model. The magnetic and transport properties were significantly influenced by the A-site cation radius and the Mn/Cr–O–Mn/Cr bond angle.
研究不足
The K doped sample was oxygen deficient due to vaporization of K, which affected its stoichiometry and properties. The study was limited to the temperature range of 80–300 K.
1：Experimental Design and Method Selection:
The materials were synthesized by the glycine-nitrate combustion method. XRD data were analyzed using Rietveld refinement technique.
2：Sample Selection and Data Sources:
La
3：7Ca25A05Mn8Cr2O3 (A = Ca, Li, Na, K) samples were prepared. List of Experimental Equipment and Materials:
X-ray powder diffractometer (XRD) Rigaku SmartLab 9 kW rotating anode, FE-SEM Quanta 200 FEG instrument for SEM and EDX, Polytronic made electromagnet for magnetic susceptibility measurements.
4：Experimental Procedures and Operational Workflow:
The solutions were stirred with constant heating to evaporate most of the water, then combusted at 150 °C, and calcined at 1100 °C.
5：Data Analysis Methods:
Rietveld refinement for XRD data, Curie-Weiss law for magnetic susceptibility, and small polaron hopping model for resistivity data.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
