Characterization: Phase purity was investigated by the X-ray diffraction (XRD, Empyrean, PANalytical) with a scan rate of 0.067 º/s using Cu K. Raman spectra were measured with Raman microscope (Horiba, Vlabinir, 532 nm). The microstructures were observed by Field Emission Scanning Emission Microscopy (Leo 1550, Carl Zeiss, Inc., Jena, Germany) for fracture surfaces. The transmission electron microscope (TEM) samples were prepared by the Focused Ion Beam (FEI Helios NanoLab 660 FIB) system and the TEM analysis was done by FEI Talos F200 ×. Average grain size was calculated from the polished surface using the line intercept method[17].The 80 nm of Pt electrodes were deposited by sputtering (Q150R Plus, Quorum) for the electrical measurement. Dielectric properties were investigated with HP 4284A precision LCR meter. The polarization-field (P-E) hysteresis loop of the BT-75nm was measured using a Sawyer-Tower circuit with a Trek Model 30/20 high voltage amplifier system (Trek, Inc., Lockport, NY).