Hernando Antonio, Ruiz-González M Luisa, Diaz Omar, Alonso José M, Martínez José L, Ayuela Andrés, González-Calbet José M, Cortés-Gil Raquel
Departamento de Ingeniería, Universidad Antonio de Nebrija, Pirineos 55, 28940 Madrid, Spain.
Instituto de Magnetismo Aplicado, UCM-ADIF-CSIC, Las Rozas, 28230 Madrid, Spain.
Nanomaterials (Basel). 2023 May 10;13(10):1601. doi: 10.3390/nano13101601.
The inclusion of La-Mn vacancies in LaMnO nanoparticles leads to a noticeable change in conductivity behavior. The sample retains its overall insulator characteristic, with a typical thermal activation mechanism at high temperatures, but it presents high magnetoconductivity below 200 K. The activation energy decreases linearly with the square of the reduced magnetization and vanishes when the sample is magnetized at saturation. Therefore, it turns out that electron hopping between Mn and Mn largely contributes to the conductivity below the Curie temperature. The influence of the applied magnetic field on conductivity also supports the hypothesis of hopping contribution, and the electric behavior can be explained as being due to an increase in the hopping probability via spin alignment.
在LaMnO纳米颗粒中引入La-Mn空位会导致导电行为发生显著变化。该样品保持其整体绝缘特性，在高温下具有典型的热激活机制，但在200 K以下呈现出高磁导率。激活能随约化磁化强度的平方线性降低，当样品饱和磁化时激活能消失。因此，结果表明在居里温度以下，Mn与Mn之间的电子跳跃对电导率有很大贡献。外加磁场对电导率的影响也支持跳跃贡献的假设，并且电行为可以解释为由于通过自旋排列导致跳跃概率增加。
