Rolled-up tubes and cantilevers by releasing SrRuO 3-Pr 0.7Ca 0.3MnO 3 nanomembranes

Abstract

Three-dimensional micro-objects are fabricated by the controlled release of inherently strained SrRuO 3/Pr 0.7Ca 0.3MnO 3/SrRuO 3 nanometer-sized trilayers from SrTiO 3 (001) substrates. Freestanding cantilevers and rolled-up microtubes with a diameter of 6 to 8 μm 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, μ-diffraction experiments reveal that a single object can represent the ensemble proving a good homogeneity of the rolled-up tubes.