Synthesis of single-bonded crystalline polymeric carbon monoxide upon laser heating at megabar pressures

Among a variety of simple molecules that undergo high pressure polymerization, carbon monoxide (CO) represents an intriguing case, and the formation of polymeric CO (pCO) at few GPa has been studied in a great number of experimental and theoretical works. Our group recently extended the pressure range where XRD and IR measurements on pCO were reported up to 50 GPa, obtaining results that suggest the stabilization of an amorphous, extended 3D network of mostly single-bonded carbon atoms, in good agreement with the previous theoretical calculations. These calculations predict the stability of crystalline pCO phases that were never experimentally attained, probably because of the kinetic hindrance of this transformation. Here we propose to deepen the knowledge on the high pressure, high temperature phase diagram of pCO by studying the potential conversion of amorphous pCO to the predicted polymeric crystalline parents following laser heating (1000-4000 K) at 100-150 GPa.