Correlated room temperature ferromagnetism and photoluminescence in Ni-doped SnO flower-like architecture synthesized via hydrothermal method

Sn1-xNixO microflowers self-assembled with nanopetals have been synthesized successfully with template-free hydrothermal growth method. Field-emission scanning electron microscopy results exhibit the flower-like architecture consist of nanopetals, which have lateral dimensions of 1–2 μm with a thickness of ∼100 nm. X-ray diffraction results show that all the samples possess typical tetragonal structure and Ni would occupy different positions (NiSn and Nii) with various concentrations. The bandgap of SnO tends to shrink firstly then widen after Ni-doping, which is caused by the sp-d exchange interactions and the Burstein-Moss effect. Meanwhile, PL and XPS measurements illustrate that tin vacancies (VSn) and oxygen vacancies (VO) were generated during the process of preparation and the VSn as the origin of the ferromagnetism in pure SnO was verified by air-anneal experiment. In addition, Ni-doping can improve the ferromagnetism via enhancing the content of VSn. This literature studies the ferromagnetism of novel SnO flower-like structure firstly and reasonably reveals the desired ferromagnetism originated from the VSn.