Near-room-temperature ferromagnetic ordering in the pressure-induced collapsed-tetragonal phase in SrCo₂P₂

We present high-pressure electrical transport, magnetization, and single-crystal X-ray diffraction data on SrCo₂P₂. X-ray diffraction shows a transition to a collapsed tetragonal (cT) structure above ~10 GPa, with the resistance measurement revealing a clear transition-like feature up to 260 K. Magnetization, magnetoresistance, and Hall measurements indicate the transition leads to a ferromagnetic ground state. Above ~30 GPa, magnetic ordering vanishes in a first-order-like manner, suggesting SrCo₂P₂ is another sample of ferromagnetic intermetallic compound that avoids quantum criticality. Density functional theory (DFT) calculations support a first-order transition between tetragonal and cT phases at ~10 GPa and show the emergence of ferromagnetic ordering in the cT phase. SrCo₂P₂ provides clear evidence that the structural, electronic and magnetic properties associated with the cT transition are strongly entangled and are not only qualitatively captured by our first principles-based calculations but are quantitatively reproduced as well.