Abstract-Probing low energy dynamics in charge-ordered NdNiO3 by terahertz time domain spectroscopy

Sarmistha Das, Gulloo Lal Prajapati,  Rakesh Rana, Dhanvir Singh Rana

https://www.sciencedirect.com/science/article/pii/S0042207X17318584

Herein, we have investigated terahertz (THz) optical properties of high quality NdNiO₃epitaxial thin film deposited on pseudocubic NdGaO₃ (001) substrate. The detailed X-ray diffraction (XRD) characterizations reveal that the film possesses orthorhombic distortion in tensile strained state, induced by the substrate. Furthermore, a clearly discernible and well defined peak appeared in the real part of THz optical conductivity (σ₁) at the low temperature charge-ordered insulating phase. The peak gradually shifted to the higher frequency as the temperature increases and eventually disappears at 120 K. The presence of this peak only at the low temperature charge-ordered phase having Fermi surface nesting in the distorted structure clearly points towards its origin of the charge density wave (CDW) excitations in NdNiO₃.