Abstract:
NiPS3 is a rare Ni-based negative charge transfer insulator with an antiferromagnetically ordered ground state with Ni spins ordered in a zigzag configuration. Recent reports indicate the presence of strong spin-phonon and spin-charge coupling in NiPS3. In this study, we report on the growth of high-quality single crystals of Ni1−xZnxPS3 (x = 0, 0.05, 0.08, 0.13, and 0.14) using the physical vapor transport method. The Raman spectra of all the compositions were measured at 300 K. We show that the phonon mode Eg(2) at 176 cm−1 attributed to the vibration of Ni ions can only be well-fitted using the Breit-Wigner Fano line shape. The parameter |1/q|, which quantifies the strength of the coupling of the phonon Eg(2) to a broad continuum, is found to have a considerably high value of 0.13. The |1/q| parameter increases with increasing Zn doping. Our findings indicate the presence of charge-phonon coupling in NiPS3 at room temperature.