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Tuyển tập các báo cáo nghiên cứu về hóa học được đăng trên tạp chí hóa hoc quốc tế đề tài : Rolled-up tubes and cantilevers by releasing SrRuO3-Pr0.7Ca0.3MnO3 nanomembranes | Deneke et al. Nanoscale Research Letters 2011 6 621 http www.nanoscalereslett.eom content 6 1 621 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Rolled-up tubes and cantilevers by releasing SrRuO3-Pr0.7Ca0.3MnO3 nanomembranes 1.2 2 3 2 2 2 Christoph Deneke 1 Elisabeth Wild Ksenia Boldyreva Stefan Baunack Peter Cendula Ingolf Monch Markus Simon4 Angelo Malachias5 Kathrin Dorr3 6 and Oliver G Schmidt2 Abstract Three-dimensional micro-objects are fabricated by the controlled release of inherently strained SrRuO3 Pr0.7Ca0.3MnO3 SrRuO3 nanometer-sized trilayers from SrTiO3 001 substrates. Freestanding cantilevers and rolled-up microtubes with a diameter of 6 to 8 pm are demonstrated. The etching behavior of the SrRuO3 film is investigated and a selectivity of 1 9 100 with respect to the SrTiO3 substrate is found. The initial and final strain states of the rolled-up oxide layers are studied by X-ray diffraction on an ensemble of tubes. Relaxation of the sandwiched Pr0.7Ca0.3MnO3 layer towards its bulk lattice parameter is observed as the major driving force for the roll-up of the trilayers. Finally p-diffraction experiments reveal that a single object can represent the ensemble proving a good homogeneity of the rolled-up tubes. PACS 81.07.-b 68.60.-p 68.37.Lp 81.16.Dn. Keywords rolled-up nanotubes and microtubes freestanding membranes ferroic oxides strain engineering Background Perovskite oxides have become a fascinating class of materials because of the wide variety of electronic properties including an intriguing ferroic magnetic or ferroelectric response for potential use in memory or sensor applications. At the same time an epitaxial strain has been demonstrated to massively change the fundamental properties of such oxides in particular affecting their electronic behavior 1-4 . A recent sensor design includes freestanding cantilevers for electromechanical devices 3 . An elegant way to form three-dimensional structures based on the .
