High-pressure single-crystal XRD and magnetic study of a octacyanoniobate-based magnetic sponge

Abstract

In the present study we report the structural and magnetic response of the 3-D cyano-bridged magnetic sponge-like system {[Mn^II(pydz)(H₂O)₂][Mn^II(H₂O)₂][Nb^IV(CN)₈]·3H₂O}_nA to external pressure up to 1.8 GPa using single-crystal crystallography and magnetic measurements. The observed pressure-induced structural changes: shrinkage of the Nb–C bonds and bending of Mn–NC–Nb linkages are responsible for the strengthening of the antiferromagnetic interactions between Mn and Nb centers and consequently for the substantial increase of the magnetic ordering temperature from 43 K to 51 K under 0.57 GPa. The observed magneto-structural response to external pressure is similar in nature to the removal of guest molecules and confirms the significant susceptibility of molecular magnetic sponges to mechanical stress.