Investigation of magnetic and transport properties of GdSbSe.

We report the detailed investigation of the magnetic, transport, and magnetocaloric effects (MCEs) of GdSbSe by magnetic susceptibilityχ(T), isothermal magnetizationM(H), resistivityρ(T,H), and heat capacityCp(T)measurements, crystallizing in the ZrSiS-type tetragonal crystal system with space group P4/nmm. Temperature-dependent magnetic susceptibility measurements revealed long-range antiferromagnetic ordering with two additional magnetic anomalies below Néel temperature (TN≈8.6K), corroborated through magnetocaloric and specific heat studies. Isothermal magnetization measurements unveil hidden metamagnetic signatures through a clear deviation from linearity. In addition, the enhanced value of the Sommerfeld coefficient (γ= 152(5) mJ mol^-1K²) suggests strong electronic correlations in GdSbSe. The entropy of magnetization derived from magnetic isotherms unfolds the field-induced transition from Inverse MCE to Conventional MCE. The detailed transport properties indicate a semimetallic behavior, strongly coupled with magnetic order. Furthermore, the linear field dependence of MR in the high-field region anticipate the possibility of Dirac-like dispersion. Deviations from Kohler's rule and non-linear Hall resistivity suggest the multiband nature of GdSbSe.