Saeedi Ahmad M A, Gerriu Fatma M, Ying Minju, Alshammari Marzook S, Heald Steve M, Li Xiaoli, Blythe Harry J, Fox A Mark, Gehring Gillian A
Department of Physics and Astronomy, University of Sheffield Hicks Building S3 7RH UK
Department of Physics, Umm Al-Qura University P.O.Box 715 Makkah 21421 Saudi Arabia.
RSC Adv. 2019 Nov 21;9(65):38001-38010. doi: 10.1039/c9ra06899f. eCollection 2019 Nov 19.
We have investigated the magnetic properties of ZnCoO thin films grown by pulsed laser deposition from targets made from pure ZnO combined with metallic Co, CoO or CoO as a function of oxygen pressure in the deposition chamber. We find that the structural and magnetic properties of films grown from targets containing CoO or CoO are similar and can be mapped on to each other by assuming that the films made from CoO require some additional oxygen to make them the same as those grown from CoO. The data suggest that the magnetism in these films is due to oxygen vacancies. Radically different properties are seen for the films grown with metallic Co in the target. In this case, there is structural evidence for the production of Zn vacancies as oxygen was added during deposition and this was accompanied by a strong increase of the magnetisation. In contrast, there was very little difference seen between the magnetic properties of the targets, which were all found to be paramagnetic, even after further annealing in air.
我们研究了通过脉冲激光沉积从由纯ZnO与金属Co、CoO或Co₃O₄制成的靶材生长的ZnCoO薄膜的磁性，该磁性是沉积室中氧气压力的函数。我们发现，由含CoO或Co₃O₄的靶材生长的薄膜的结构和磁性相似，并且通过假设由CoO制成的薄膜需要一些额外的氧气才能使其与由Co₃O₄生长的薄膜相同，可以将它们相互对应起来。数据表明，这些薄膜中的磁性归因于氧空位。对于靶材中含有金属Co生长的薄膜，观察到了截然不同的性质。在这种情况下，有结构证据表明在沉积过程中添加氧气时产生了Zn空位，并且这伴随着磁化强度的强烈增加。相比之下，靶材的磁性之间几乎没有差异，即使在空气中进一步退火后，所有靶材都被发现是顺磁性的。
