Local Valence and Hole-Doping Effect on Magnetic Properties in Double Perovskite La2NiMnO6 |
| |
Authors: | Yuqiao Guo Lei Shi Shiming Zhou Jiyin Zhao Shiqiang Wei |
| |
Affiliation: | 1. Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, People’s Republic of China 2. National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230029, People’s Republic of China
|
| |
Abstract: | Local valence and Ca-doping effect in polycrystalline La2NiMnO6 have been investigated by using X-ray diffraction, X-ray absorption spectroscopy, Raman spectrum, and magnetometry. The refinement of X-ray diffraction data shows that all the samples are crystallized in pure double perovskite phase. The refined Ni(Mn)–O bond lengths and X-ray absorption spectroscopy provide evidences that the oxidation state of Ni and Mn ions in bulk La2NiMnO6 has the Ni2+ and Mn4+ configuration and the decrease of average A-site valence caused by Ca doping is compensated by the increase of Ni valence, while Mn keeps unchanged. As the Ca-doping content increases, the peak shapes of Raman spectroscopy exhibit an increase in the linewidth and decrease in the intensity, respectively, which reveals the increase the disorder of Ni–O bond length and the decrease of Ni/Mn ordering degree. Both the paramagnetic–ferromagnetic transition temperature and the saturation magnetization exhibit decrease with the increase of Ca-doping content, which are attributed to the decrease of Ni–O–Mn bond angle and the increase of Ni/Mn antisite disorder, respectively. All those behaviors can be ascribed to the valence state change of Ni ion caused by hole doping. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|