A spin valve based on hole-doped manganite electrodes and epitaxial matched SrTiO3 (STO) spacer has not yet realized their full potential. Along with stabilization of bulk-like properties of manganites at the interface (“dead” layer) the reducing of spacer thickness plays a key role in pursuing of room-temperature operation of magnetic tunnel junctions (MTJs). The interface roughness as well as defects embedded in the insulator layer define a minimal thickness of spacer about 5-6 u.c. Recently, however, the independent magnetic behavior of ferromagnetic layers in epitaxial (La0.6Sr0.4)MnO3 (LSMO) - (La0.6Sr0.4)(Mn0.95Ru0.05)O3 (LSMRO) heterostructure have been observed for STO 3 u.c. barrier layer1.  Optimization of the growth conditions made possible to create flat and smooth interfaces that in turn led to a significant reducing of the critical thickness for decoupling. The further reducing of the critical thickness faces with the inherent in low oxygen pressure techniques defects like oxygen vacancies that may lead to unwanted magnetism in the SrTiO3 tunnel barrier2.   In present study we employ metalorganic aerosol deposition (MAD) technique, which is assumed to provide an exact oxygen stoichiometry in the grown layers due to a high (PO2 ~ 0.21 atm) gas pressure. The heterostructure composed from low coercivity LSMO, STO -spacer and high coercivity LSMRO layers was grown on STO(100) substrate. The thickness accuracy of 2 u.c. STO barrier was achieved by calibration of the precursor dosing units and in-situ control with optical ellipsometry. The surface of trilayer examined by atomic force microscopy clearly demonstrates flat terraces of a one unite cell height (~0.4 nm) with RMS 0.35 nm. X-ray diffractometry and X-ray reflectivity analysis accompanied by simulation and fitting indicates a highly ordered crystalline structure with very smooth interfaces. Transmission electron microscopy characterization attests that the interfaces obtained by the MAD growth technique are extremely sharp with a little or no inter-diffusion of species across the interfaces. Magnetic properties were characterized by a superconducting quantum interference device magnetometer and magneto-optical Kerr effect. Room temperature hysteresis loops were defined by parallel and antiparallel states of ferromagnetic two layers with a high difference between switching fields. The coercive field of the LSMO layer was not affected by magnetic harder LSMRO layer that indicates full decoupling between ferromagnetic electrodes. Low temperature (10K) magnetic hysteresis shows that coupling between top and bottom ferromagnetic layers increases, notwithstanding, preserving the independent switching with a large (about an order) contrast.   In summary, we have shown that magnetically sharp heterointerface in manganite based MTJs with perovskite STO barrier persists up to 2 u.c. thickness of the spacer. MAD growth technique provides exceptional structural quality of interfaces without defects driven by oxygen deficiency.