Destruction dynamics of a heterogeneous body (diorite) under friction

Abstract

Triboluminescence bursts are observed in two heterogeneous (diorite) specimens under friction against each other. Triboluminescence appears upon the relaxation of excited free ≡Si–O^– radicals and Fe³⁺ ions and the capture of electrons with acceptor traps formed upon the destruction of the plagioclase crystal lattice. The analysis of the time dependence of these bursts shows that the friction surfaces accumulate clusters, in which the concentration of free ≡Si–O^– radicals and electron traps is at least an order of magnitude higher than in their surrounding. The time interval between the appearance of two sequential clusters variates from 0.1 to 1 μs. The linear sizes of clusters are ~0.5 μm.