Controllable oxygen vacancies, orbital occupancy and magnetic ordering in SrCoO3-delta films

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	Controllable oxygen vacancies, orbital occupancy and magnetic ordering in SrCoO3-delta films
	Gu, YD; Song, C; Zhang, HR; Wang, ZC; Cui, B; Li, F; Peng, JJ; Saleem, MS; Wang, GY; Zhong, XY
刊名	JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
	2018-05-15
卷号	454 页码:228-236
关键词	Transition-metal Oxides Phase-transformation Redox Reactions Ground-state Nanoscale Srcoo2.5 Defects Physics
ISSN号	0304-8853
英文摘要	Epitaxial strain imposed in complex oxide ultrathin films is recognized as a powerful tool for controlling the ground state of correlated electron system. Here, we achieved simultaneous control of oxygen vacancies, orbital occupancy and magnetic ordering through the facile application of epitaxial strain, both tensile and compressive, in SrCoO3-delta oxygen "sponge" material rather than the ordinary manganites. The oxygen vacancies are enhanced greatly as the strain changes from smaller tensile 1.0% to larger tensile 2.0%, then to moderate compressive -1.0% in SrCoO3-delta films, associated with 3 - delta varying from similar to 2.90 to similar to 2.835, then to similar to 2.72. Highest saturated magnetization is found in the thin films in small tension on La0.3Sr0.7Al0.65Ta0.35O3 substrate and lower values are found in larger tension on SrTiO3 and lowest values in moderate compression on LaAlO3. Meanwhile, electrons prefer to occupy the in-plan oriented orbitals for the tensile strain, in contrast to the preferential out-of-plane orbital occupancy for the compressive state associated with coupled intermediate spin-Co4+ (t(2g)(4) e(g)(1))/high spin-Co3+ (t(2g)(4) e(g)(2)) in different proportions depending on strain states. Such controllable spin and orbital configurations lead to more robust magnetization in tensile strained SrCoO3-delta films than in its compressive counterpart. Our findings provide a nostrum for tailoring and controlling new magnetic, electronic and ionically active properties with strain engineering and further enrich orbital physics in cobaltites. (C) 2018 Elsevier B.V. All rights reserved.; Epitaxial strain imposed in complex oxide ultrathin films is recognized as a powerful tool for controlling the ground state of correlated electron system. Here, we achieved simultaneous control of oxygen vacancies, orbital occupancy and magnetic ordering through the facile application of epitaxial strain, both tensile and compressive, in SrCoO3-delta oxygen "sponge" material rather than the ordinary manganites. The oxygen vacancies are enhanced greatly as the strain changes from smaller tensile 1.0% to larger tensile 2.0%, then to moderate compressive -1.0% in SrCoO3-delta films, associated with 3 - delta varying from similar to 2.90 to similar to 2.835, then to similar to 2.72. Highest saturated magnetization is found in the thin films in small tension on La0.3Sr0.7Al0.65Ta0.35O3 substrate and lower values are found in larger tension on SrTiO3 and lowest values in moderate compression on LaAlO3. Meanwhile, electrons prefer to occupy the in-plan oriented orbitals for the tensile strain, in contrast to the preferential out-of-plane orbital occupancy for the compressive state associated with coupled intermediate spin-Co4+ (t(2g)(4) e(g)(1))/high spin-Co3+ (t(2g)(4) e(g)(2)) in different proportions depending on strain states. Such controllable spin and orbital configurations lead to more robust magnetization in tensile strained SrCoO3-delta films than in its compressive counterpart. Our findings provide a nostrum for tailoring and controlling new magnetic, electronic and ionically active properties with strain engineering and further enrich orbital physics in cobaltites. (C) 2018 Elsevier B.V. All rights reserved.
学科主题	Materials Science, Multidisciplinary ; Physics, Condensed Matter
语种	英语
资助机构	National Natural Science Foundation of China [51671110, 51571128, 51590883, 51771198]; National Key Research and Development Program [2016YFA0203800, 2016YFA0300701]
公开日期	2018-06-05
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/79309]
专题	金属研究所_中国科学院金属研究所
通讯作者	Liu, W (reprint author), Chinese Acad Sci, Inst Met Res, Shenyang 110016, Liaoning, Peoples R China.
推荐引用方式 GB/T 7714	Gu, YD,Song, C,Zhang, HR,et al. Controllable oxygen vacancies, orbital occupancy and magnetic ordering in SrCoO3-delta films[J]. JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS,2018,454:228-236.
APA	Gu, YD.,Song, C.,Zhang, HR.,Wang, ZC.,Cui, B.,...&Liu, W .(2018).Controllable oxygen vacancies, orbital occupancy and magnetic ordering in SrCoO3-delta films.JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS,454,228-236.
MLA	Gu, YD,et al."Controllable oxygen vacancies, orbital occupancy and magnetic ordering in SrCoO3-delta films".JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS 454(2018):228-236.