Reversible magnetoelectric switching in multiferroic three-dimensional nanocup heterostructure films

• Published in: NPG Asia materials Vol. 11; no. 1; pp. 1 - 10
• Main Authors: An, Hyunji, Hong, Hyo Jin, Jo, Yong-Ryun, Jung, Soon-Gil, Kim, Sangmo, Kim, Sangwoo, Lee, Jongmin, Choi, Hojoong, Yoon, Hongji, Kim, So-Young, Song, Jaesun, Jeong, Sang Yun, Lee, Byoung Hun, Koo, Tae-Yeong, Park, Tuson, Ko, Kyung-Tae, Kim, Bongjae, Kim, Bong-Joong, Bark, Chung Wung, Lee, Sanghan
• Format: Journal Article
• Language: English
• Published: Tokyo Nature Publishing Group 29.11.2019
• Subjects: Architecture; Bismuth; Brewing; Cobalt ferrites; Coupling; Dielectric strength; Electric fields; Electrical properties; Ferroelectric materials; Ferroelectricity; Ferromagnetic materials; Ferromagnetic phases; Heterostructures; Iron; Lanthanum; Magnetic properties; Magnetic signals; Morphology; Multiferroic materials; Nanocomposites; Nanostructure; Nucleation; Pulsed laser deposition; Pulsed lasers; Self-assembly; Surface tension; Switches; Switching; Thin films
• ISSN: 1884-4049; 1884-4057
• DOI: 10.1038/s41427-019-0172-4

Abstract Self-assembled nanocomposite films containing ferroelectric and ferromagnetic phases have attracted enormous research interest because they are the most promising candidates for practical multiferroic applications. However, obtaining a genuine magnetoelectric (ME) coupling effect is still challenging in this research area. To substantially improve the ME effect, new heterostructure designs with efficient strain control between two phases are urgently needed. Herein, a novel three-dimensional (3D) nanocup architecture of a heterostructure film is developed. To establish the unique architecture, a heavily Co, Fe-doped ferroelectric Bi 3.25 La 0.75 Ti 3 O 12 (BLT) target was used during the growth of BLT thin films via pulsed laser deposition. Consequently, 3D nanocup-structured CoFe 2 O 4 (CFO) particles formed inside the BLT via spontaneous nucleation and agglomeration. The 3D nanocup BLT-CFO film exhibited magnetically controlled reversible dielectric switching, which is direct evidence of strong ME coupling caused by the efficient interfacial strain coupling and low leakage of the novel nanocup architecture. The obtained results strongly suggest that the 3D nanocup heterostructure film significantly improves the ME coupling effect. In addition, we propose a new paradigm in the architecture design of self-assembled nanocomposite films for diverse multifunctional devices.