Oxygen Partial Pressure during Pulsed Laser Deposition: Deterministic Role on Thermodynamic Stability of Atomic Termination Sequence at SrRuO 3 /BaTiO 3 Interface

• Published in: ACS applied materials & interfaces 2017-08, Vol.9 (32), p.27305-27312
• Main Authors: Shin, Yeong Jae, Wang, Lingfei, Kim, Yoonkoo, Nahm, Ho-Hyun, Lee, Daesu, Kim, Jeong Rae, Yang, Sang Mo, Yoon, Jong-Gul, Chung, Jin-Seok, Kim, Miyoung, Chang, Seo Hyoung, Noh, Tae Won
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.7b07813

With recent trends on miniaturizing oxide-based devices, the need for atomic-scale control of surface/interface structures by pulsed laser deposition (PLD) has increased. In particular, realizing uniform atomic termination at the surface/interface is highly desirable. However, a lack of understanding on the surface formation mechanism in PLD has limited a deliberate control of surface/interface atomic stacking sequences. Here, taking the prototypical SrRuO /BaTiO /SrRuO (SRO/BTO/SRO) heterostructure as a model system, we investigated the formation of different interfacial termination sequences (BaO-RuO or TiO -SrO) with oxygen partial pressure (P ) during PLD. We found that a uniform SrO-TiO termination sequence at the SRO/BTO interface can be achieved by lowering the P to 5 mTorr, regardless of the total background gas pressure (P ), growth mode, or growth rate. Our results indicate that the thermodynamic stability of the BTO surface at the low-energy kinetics stage of PLD can play an important role in surface/interface termination formation. This work paves the way for realizing termination engineering in functional oxide heterostructures.