Temperature-dependent Raman scattering and x-ray diffraction studies of charge density wave order in PrSb2

Abstract

The charge density wave (CDW) transition in the PrSb2 compound has been systematically investigated through variable-temperature Raman scattering, x-ray diffraction, and electrical resistivity measurements. A non-monotonic anomaly in resistivity is observed near 100 K. Below this temperature, an amplitude mode appears in Raman spectra—a well-established fingerprint of CDW order—that redshifts and weakens upon warming. X-ray diffraction reveals a change in lattice parameter slope at 100 K, evidencing electron-lattice coupling and confirming CDW instability without structural phase transition. Notably, no anomalies were found in magnetization or specific heat near 100 K. Furthermore, at T = 1.8 K and with H ⊥ c axis, a series of fractional magnetization plateaus are observed, resembling the “devil's staircase.” These findings show that PrSb2 hosts coexisting CDW instability and antiferromagnetic order with strong magneto-transport responses, making it a rare platform for studying quantum order interactions in correlated electron systems.