High-pressure phase of CrSb2 : A new quasi-one-dimensional itinerant magnet with competing interactions

We have synthesized the high-pressure form of $\mathrm{CrS}{\mathrm{b}}_{2}$ with $\mathrm{CuA}{\mathrm{l}}_{2}$-type structure under 7 GPa and 700 \ifmmode^\circ\else\textdegree\fi{}C, and characterized its structural, transport, and magnetic properties by a suite of measurement techniques over a broad range of temperature, magnetic field, and pressure. In addition to previously reported ferromagnetic (FM) transition at ${T}_{\mathrm{C}}\ensuremath{\approx}160$ K, we discover another antiferromagnetic spin-density-wave (SDW) transition at ${T}_{\mathrm{s}}\ensuremath{\approx}90$ K, which is characterized by FM sheets of spins in the $ab$ plane that vary along the $c$ axis as determined by neutron powered diffraction. Pronounced anomalies around these two magnetic transitions are visible only in the lattice parameter $c$, signaling a strong spin-lattice coupling along the -Cr-Cr-Cr- infinite linear chain. We find that the application of magnetic field can suppress the SDW phase and stabilize the FM state down to the lowest temperature above ${\ensuremath{\mu}}_{0}{H}_{\mathrm{c}}\ensuremath{\approx}3$ T, around which a peculiar non-Fermi-liquid behavior with reduced effective mass emerges. On the other hand, the application of high pressure induces complex evolution of the magnetic states, i.e., the FM order is lowered while the SDW order is enhanced quickly until they merge together into a single antiferromagnetic transition, which is suppressed completely at ${P}_{\mathrm{c}}\ensuremath{\approx}9$ GPa. We observe near ${P}_{\mathrm{c}}$ non-Fermi-liquid behavior and enhancement of effective mass, which indicates the possible occurrence of magnetic quantum critical point. No superconductivity was observed down to 2 K around ${P}_{\mathrm{c}}$.