Combining Raman spectroscopy and synchrotron X-ray diffraction to unveil the order types in A3CaNb2O9 (A = Ba, Sr) complex perovskites - Rodrigues, João Elias Figueiredo Soares; Costa, Renilton Correia da; Pizani, Paulo Sergio; Hernandes, Antônio Carlos; Alonso, José Antonio (Journal of Raman Spectroscopy, 2022)