Acoustic Relaxation Effect inMn3O4

Abstract

Internal friction effects occur in ${\mathrm{Mn}}_3$ ${\mathrm{O}}_4$ which have been attributed to stress-induced change in the distribution of ${\mathrm{Mn}}^{++}$ and ${\mathrm{Mn}}^{++++}$. The activation energy is 0.4 ev per unit of process responsible for the internal friction.