Is the surface of Hofmann-like spin-crossover {Fe(pz)[Pt(CN)]} the same as its bulk?

Temperature dependent X-ray photoemission spectroscopy (XPS) has been employed to examine the spin-crossover (SCO) transition in the nanocrystals of 3D Hoffman-like {Fe(pz)[Pt(CN) 4 ]}. Consistent with the existing literature, the temperature-dependent variations in the Fe 2p core-level spectrum provide unambiguous evidence of the spin-state transition in this SCO complex. One of the many possible reasons behind a lack of discernible temperature-driven shifts in the binding energies of both the N 1s core-level components could be the immunity of its HS electronic configuration to thermal fluctuations. The high-spin fraction versus temperature plot, extrapolated from the XPS measurements, reveals that the surface of the nanocrystals of {Fe(pz)[Pt(CN) 4 ]} is in the high-spin state at room temperature, rendering it promising for room-temperature spintronics and quantum information science applications. High-spin fraction of {Fe(pz)[Pt(CN) 4 ]} extrapolated from XPS (black and blue triangles) and compared with normalised magnetic susceptibility measurements (red curve).