BaTiO₃ is a classical ferroelectric studied for last one century for its ferroelectric properties. Lattice dynamics of BaTiO₃ is crucial as the utility of devices is governed by phonons. In this work, we show that traditional characterization of the polar phonon modes is ambiguous and often misinterpreted. By combining Raman, Neutron and X-ray diffraction, dielectric spectroscopic observations with first principle calculations, we have re-examined the character of the normal modes of phonons of tetragonal BaTiO₃. We obtained Eigen displacements of vibrational modes through DFT calculations and reclassified the polar modes being Slater (Ti–O), Last (Ba–TiO₃) and Axe (BO₆) vibrations by correlating experimental and theoretical calculations. The study thus provides authentic nomenclature of the polar modes.

BaTiO ₃是一种经典的铁电体，因其铁电特性而研究了一个世纪。BaTiO _{3 的}晶格动力学是至关重要的，因为设备的效用是由声子控制的。在这项工作中，我们表明极性声子模式的传统表征是模棱两可的，并且经常被误解。通过结合拉曼、中子和X射线衍射、介电光谱观察和第一性原理计算，我们重新审视了四方BaTiO ₃声子的正常模式的特征。我们通过 DFT 计算获得了振动模式的本征位移，并将极模式重新分类为 Slater (Ti-O)、Last (Ba-TiO ₃ ) 和 Ax (BO ₆) 振动通过关联实验和理论计算。因此，该研究提供了极坐标模式的真实命名法。