Supplement Number 1: experimental procedure, Supplement Number 2: Supporting figures, Supplement Number 3: Supporting table.

the experimental procedure, XRD patterns of bulk specimens, Rietveld refinement of powder specimens utilizing Cc and R3c structural models for BNT-Mn single crystals, frequency dependence of relative permittivity, temperature-dependent loss tangent tanδ of unpoled and poled states, εr and in-situ d33 values as a function of temperature for the LNQ specimens, relaxor diffuseness factor, phase value variations along the red and blue lines at selected temperatures, local phase and amplitude curves of AG and LNQ specimens, and EDS data of BNT-Mn single crystals.