Akbar S, Hasanain S K, Ivashenko O, Dutka M V, Akhtar N, De Hosson J Th M, Ali N Z, Rudolf P
Zernike Institute for Advanced Materials, University of Groningen Nijenborgh 4 NL-9747AG Groningen The Netherlands
Department of Physics, Quaid-i-Azam University Islamabad Pakistan.
RSC Adv. 2019 Jan 30;9(7):4082-4091. doi: 10.1039/c9ra00455f. eCollection 2019 Jan 25.
We report on the ferromagnetism of Sn Zn O ( ≤ 0.1) hierarchical nanostructures with various morphologies synthesized by a solvothermal route. A room temperature ferromagnetic and paramagnetic response was observed for all compositions, with a maximum in ferromagnetism for = 0.04. The ferromagnetic behaviour was found to correlate with the presence of zinc on substitutional Sn sites and with a low oxygen vacancy concentration in the samples. The morphology of the nanostructures varied with zinc concentration. The strongest ferromagnetic response was observed in nanostructures with well-formed shapes, having nanoneedles on their surfaces. These nanoneedles consist of (110) and (101) planes, which are understood to be important in stabilizing the ferromagnetic defects. At higher zinc concentration the nanostructures become eroded and agglomerated, a phenomenon accompanied with a strong decrease in their ferromagnetic response. The observed trends are explained in the light of recent computational studies that discuss the relative stability of ferromagnetic defects on various surfaces and the role of oxygen vacancies in degrading ferromagnetism an increase in free electron concentration.
我们报道了通过溶剂热法合成的具有各种形貌的SnZnO（≤0.1）分级纳米结构的铁磁性。在所有组成中均观察到室温铁磁性和顺磁性响应，其中当= 0.04时铁磁性最大。发现铁磁行为与替代Sn位点上锌的存在以及样品中低氧空位浓度相关。纳米结构的形貌随锌浓度而变化。在形状良好、表面有纳米针的纳米结构中观察到最强的铁磁响应。这些纳米针由（110）和（101）平面组成，据信这些平面对于稳定铁磁缺陷很重要。在较高锌浓度下，纳米结构会被侵蚀和团聚，这种现象伴随着它们铁磁响应的强烈降低。根据最近的计算研究对观察到的趋势进行了解释，这些研究讨论了各种表面上铁磁缺陷的相对稳定性以及氧空位在降低铁磁性（自由电子浓度增加）中的作用。
