Rolled-up tubes and cantilevers by releasing SrRuO3-Pr0.7Ca0.3MnO3 nanomembranes

Three-dimensional micro-objects are fabricated by the controlled release of inherently strained SrRuO₃/Pr_0.7Ca_0.3MnO₃/SrRuO₃ nanometer-sized trilayers from SrTiO₃(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 Pr_0.7Ca_0.3MnO₃ 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.