LAUSR

Here, we demonstrate the power of polarized Raman spectroscopy (PRS) in tracing microscopic atomic displacements in a single crystalline material. Crystalline materials often show extremely small microscopic atomic displacements as a function of temperature, pressure, electric and magnetic field or across phase transition which can be traced by our defined method using routinely available Raman spectrometers and with the knowledge of Raman tensors and phonon deformation potentials. Importantly, the information is directional and provides a vital information about the root cause of polarization in ferroelectrics, multiferroics. In this article, the method is demonstrated by carrying out the temperature and directional dependent PRS study on BaTiO3 single crystal, where the Ti ion displacement across the various phase transitions is well documented. The value of the ferroelectric polarization and its component along different crystallographic axes as well as their temperature variations calculated from the Ti displacement obtained by our defined method matches well with the reported results obtained from other techniques. This method thus can be applied to obtain quantitative information of atomic displacements in a crystalline solid.