Pressure-induced magnetic phase and structural transition in SmSb2

Motivated by the recent discovery of unconventional superconductivity around a magnetic quantum critical point in pressurized CeSb2, here we present a high-pressure study of an isostructural antiferromagnetic (AFM) SmSb2 through electrical transport and synchrotron x-ray diffraction measurements. At P-C similar to 2.5 GPa, we found a pressure-induced magnetic phase transition accompanied by a Cmca -> P4/nmm structural phase transition. In the pristine AFM phase below P-C, the AFM transition temperature of SmSb2 is insensitive to pressure; in the emergent magnetic phase above P-C, however, the magnetic critical temperature increases rapidly with increasing pressure. In addition, at ambient pressure, the magnetoresistivity (MR) of SmSb2 increases suddenly upon cooling below the AFM transition temperature and presents linear nonsaturating behavior under high field at 2 K. With increasing pressure above P-C, the MR behavior remains similar to that observed at ambient pressure, both in terms of temperature- and field-dependent MR. This leads us to argue an AFM-like state for SmSb2 above P-C. Within the investigated pressure of up to 45.3 GPa and the temperature of down to 1.8 K, we found no signature of superconductivity in SmSb2.