High-temperature ferromagnetic metallic phase in LaMnO_(3)/Sr_(3)Al_(2)O_(6)heterostructure  

作　　者：Di Wang Bin He Jinrui Guo Qixiang Wang Chaoqun Shi Yue Han Hong Fang Jie Wang Nana Zhang Peng Zhang Yanan Chen Changwen Zhang Weiming Lü Shishen Yan 

机构地区：[1]Spintronics Institute,School of Physics and Technology,University of Jinan,Jinan,250022,China [2]Condensed Matter Science and Technology Institute,School of Instrumentation Science and Engineering,Harbin Institute of Technology,Harbin,150080,China [3]School of Physics,Shandong University,Jinan,250100,China

出　　处：《Journal of Materials Science & Technology》2022年第24期69-74,共6页材料科学技术（英文版）

基　　金：financial support from the National Natural Science Foundation of China(No.12074149);support from the Natural Science Foundation of Shandong Province(No.ZR2020QA057);support from the National Natural Science Foundation of China(No.51871112);the Major Basic Research Projects of Shandong Province(No.ZR2020ZD28);the 111 Project(No.B13029);support from the Taishan Scholar Project of Shandong Province(No.ts20190939);the Independent Cultivation Program of Innovation Team of Ji’nan City(No.2021GXRC043)。

摘　　要：To achieve a flexible single-crystal multifunctional membrane,the freestanding process of a rigid epitaxial transition metal oxide thin film via a buffered water-dissolution sacrificial layer has attracted reasonable attentions.Owing to the difference in chemical potential,specific element affinity,and lattice constant between the target membrane and the sacrificial layer,the freestanding process may cause an indelible change of physics property once the target thin film is sensitive to the above factors.Here,the heterostructures composed of the generally adopted sacrificial layer Sr_(3)Al_(2)O_(6)(SAO)and LaMnO_(3)(LMO)have been systematically investigated.The electrical and magnetic properties of LMO show extreme sensitivity to the thickness of SAO(tSAO).Then we have also found that LMO/SAO heterostructures can exhibit the coexistence of two ferromagnetic phases,the significantly enhanced Curie temperature~342 K,and the large magnetoresistance-23.3%at 300 K,which is similar to the optimal-doped manganite such as La_(2/3)Sr_(1/3)MnO_(3).X-ray diffraction results show that continuously tunable strain from out-of-plane tension to relaxation and then to compression can be generated by adjusting tSAO.This strain can stabilize the migrated oxygen from LMO to SAO,which is induced by the large oxygen affinity difference between Bsite Mn and Al.It is believed that these unexpected electrical/magnetic phenomena are originated from the combined effects of interfacial element diffusion and strain.Our study provides a strategy for designing new magnetic phases,and a reference for the fundamental understanding of strongly correlated transition metal oxide systems in the freestanding process.

关 键 词：Sr_(3)Al_(2)O_(6) LaMnO_(3) Oxygen affinity Oxygen ions migration Strain effects 

分 类 号：O469[理学—凝聚态物理]