Remarkable impact of KBr pelletization on spin switching: probing Hofmann-type 3D spin-crossover frameworks by solid-state optical spectroscopy

Abstract

KBr pelletization profoundly influences the thermal and photoinduced spin-crossover behavior in dehydrated [Fe_1−xM_x(pz)Pd(CN)₄] in bulk, nanoparticles and polymer composite forms by inducing tensile strain, defects, dopant-rattling, and electrostatic perturbations that alter ΔE⁰_HL and cooperativity. It enables hidden thermal switching, dopant dynamics, and quantum-tunneling-driven LIESST relaxation, revealing mechanical processing as a versatile tool to tune spin-state energetics and cooperativity.