The Role of Phonons and Defects in the Recently Discovered Non-Cubicity of SrVO₃

The correlated nature of SrVO₃ underlies its potential for advanced applications that include transparent conductors used in photovoltaics and low work-function technologies like electron emitters. While its interesting electronic nature and functionalities have been widely studied, the finer details of the lattice dynamics and structure of SrVO₃ (to date only the cubic perovskite form has been observed) relative to its ferroelectric (BaTiO₃) and quantum paraelectric (SrTiO₃) cousins have largely eluded both the chemistry and physics communities. Motivated by reports of imaginary phonon modes in DFT calculations of cubic SrVO₃ and employing high quality neutron scattering data, we indeed find that the neutron diffraction and corresponding pair distribution function of SrVO₃ over a range of temperatures are better modeled to lower symmetry structures. Contrary to previous work, our DFT calculations show that the non-cubicity of SrVO₃ does not result from lattice instabilities but rather defects likely introduced from common synthesis procedures.