Emission of neutral Mg from single crystal MgO during abrasion with diamond

Abstract

We report observations of atomic, neutral Mg emitted from single crystal MgO during abrasion with a diamond stylus. These emissions take the form of bursts, where the onset of each burst coincides with a slip event often associated with the passage of the stylus over a cleavage step. After the onset, the emission intensity grows gradually to a peak, then drops sharply. Similar bursts of neutral Mg are observed when indented single crystal MgO is heated to temperatures above 1300°C. We attribute these bursts to the emission of neutral Mg during the relaxation of dislocation-related structures produced by mechanical deformation. Strain energy released as these structures annihilate at the surface drive Mg emission and heat the surrounding material. This heating accelerates subsequent relaxation, increasing the emission intensity until relaxation is complete and the emission rate drops sharply.

Probing the tribochemical degradation of hydrogenated amorphous carbon using mechanically stimulated gas emission spectroscopy

“…While thermal desorption can be confidently ruled out, there are firm evidences [56,[65][66][67][68][69][70] that the MSGE can be related to fracture, abrasion, plastic deformation and other forms of material damage. In fact, certain conformity of the MSGE and the wear behaviour can be easily observed.…”

Operando exploration of tribochemical decomposition in synthetic FeS2 thin film and mineral iron pyrite

“…By integrating this technique with mass spectrometry, it becomes possible to accurately detect and quantify volatile products that swily propagate in vacuum from buried mechanical interfaces, thereby facilitating the real-time characterization of tribochemical reactions. [27][28][29] Up to now, mass spectrometry of emitted gases has been successfully employed across various studies, revealing tribochemical processes within diverse materials such as amorphous carbon, 30,31 polymers, 32 metal alloys, 29,33 minerals [34][35][36][37] and hydrides. 33,38 In the present study, our focus is on investigating the tribochemical processes on the submicrometre scale in two forms of iron sulde: natural mineral and synthetic thin lm.…”