Ni Shu, Houwman Evert, Gauquelin Nicolas, Chezganov Dmitry, Van Aert Sandra, Verbeeck Johan, Rijnders Guus, Koster Gertjan
MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente, Enschede 7500 AE, Netherlands.
Electron Microscopy for Materials Research (EMAT), Department of Physics, University of Antwerp, Antwerpen BE-2020, Belgium.
ACS Appl Mater Interfaces. 2024 Mar 13;16(10):12744-12753. doi: 10.1021/acsami.3c16241. Epub 2024 Feb 29.
Because of its low hysteresis, high dielectric constant, and strong piezoelectric response, Pb(MgNb)O-PbTiO (PMN-PT) thin films have attracted considerable attention for the application in PiezoMEMS, field-effect transistors, and energy harvesting and storage devices. However, it remains a great challenge to fabricate phase-pure, pyrochlore-free PMN-PT thin films. In this study, we demonstrate that a high deposition rate, combined with a tensile mismatched template layer can stabilize the perovskite phase of PMN-PT films and prevent the nucleation of passive pyrochlore phases. We observed that an accelerated deposition rate promoted mixing of the B-site cation and facilitated relaxation of the compressively strained PMN-PT on the SrTiO (STO) substrate in the initial growth layer, which apparently suppressed the initial formation of pyrochlore phases. By employing La-doped-BaSnO (LBSO) as the tensile mismatched buffer layer, 750 nm thick phase-pure perovskite PMN-PT films were synthesized. The resulting PMN-PT films exhibited excellent crystalline quality close to that of the STO substrate.
由于其低滞后、高介电常数和强压电响应，铌镁酸铅-钛酸铅（PMN-PT）薄膜在压电微机电系统、场效应晶体管以及能量收集和存储设备中的应用引起了广泛关注。然而，制备纯相、无焦绿石的PMN-PT薄膜仍然是一个巨大的挑战。在本研究中，我们证明了高沉积速率与拉伸失配模板层相结合可以稳定PMN-PT薄膜的钙钛矿相，并防止无源焦绿石相的成核。我们观察到，加速沉积速率促进了B位阳离子的混合，并有助于初始生长层中受压应变的PMN-PT在SrTiO（STO）衬底上的弛豫，这显然抑制了焦绿石相的初始形成。通过使用镧掺杂的BaSnO（LBSO）作为拉伸失配缓冲层，合成了750 nm厚的纯相钙钛矿PMN-PT薄膜。所得的PMN-PT薄膜表现出与STO衬底相近的优异晶体质量。
