Surface modeling and chemical solution deposition of SrO(SrTiO3)n Ruddlesden–Popper phases

✍ Scribed by M. Zschornak; S. Gemming; E. Gutmann; T. Weißbach; H. Stöcker; T. Leisegang; T. Riedl; M. Tränkner; T. Gemming; D.C. Meyer

• Book ID: 103999110
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 995 KB
• Volume: 58
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2010.04.035

✦ Synopsis

Strontium titanate (STO) is a preferred substrate material for functional oxide growth, whose surface properties can be adjusted through the presence of Ruddlesden-Popper (RP) phases. Here, density functional theory (DFT) is used to model the (1 0 0) and (0 0 1) surfaces of SrO(SrTiO 3 ) n RP phases. Relaxed surface structures, electronic properties and stability relations have been determined. In contrast to pure STO, the near-surface SrO-OSr stacking fault can be employed to control surface roughness by adjusting SrO and TiO 2 surface rumpling, to stabilize SrO termination in an SrO-rich surrounding or to increase the band gap in the case of TiO 2 termination. RP thin films have been epitaxially grown on (0 0 1) STO substrates by chemical solution deposition. In agreement with DFT results, the fraction of particular RP phases n = 1-3 changes with varying heating rate and molar ratio Sr:Ti. This is discussed in terms of bulk formation energy.