Paramagnetic Resonance of Defects Introduced Near the Surface of Solids by Mechanical Damage

Abstract

Electron spin resonance characteristics of a number of materials subjected to violent mechanical treatment are reported. A line with g=2.0055 observed in silicon is attributed to defects introduced near the surface by mechanical damage. The resonance properties are uninfluenced by interactions of the silicon surface with atmospheric gases. Similar lines appear in germanium, silicon carbide, and diamond. The dominant line produced by mechanical damage to MgO is attributed to F centers. Similar lines are observed in other II-VI compounds. Results are also reported for a number of other materials. Similarity between defects produced mechanically and by fast neutrons is noted.

NMR and AFM investigations of nanocavities on the double rare-earth fluoride crystal surface

“…The corresponding value of the parameter "surface roughness" for LiF equals 1.6 nm. As concerns the defect centers on the surface of crystals CaF2 and LiF, no EPR signals were previously detected for such centers [ 16], which is in good correlation with our concepts on the nature and the properties of the nanocavities on the surface of crystals of the double rare-earth fluorides. An additional confirmation for this argument can be found in NMR cryoporometry data of a finely dispersed CaF2 powder, prepared by the same technique as the LiYF 4 powder.…”

Multi-Photon Phosphor Feasibility Research

“…It is also a known fact that milling or any other disruptive mechanical treatment of a freshly synthesized polycrystalline material can introduce lattice distortions that result or assist in the generation of defects [66][67][68]. For the case of halophosphate , the brightness of luminescence decreases up to 20% (depending on the duration of grinding) with the dislocation density increasing from 10 8 to 10 10 cm -2 [69].…”

Electron paramagnetic resonance evaluation of defects at the (100)Si/Al2O3interface

“…Errors given Previous work [9] has shown that such a resonance line can be present in addition to the lines due to P b0 and P b1 defects. This line is attributed to silicon dangling bonds (Si-db) and is well known to occur in damaged silicon [14]. The fit to these spectra, included in figure 1, shows each spectrum can be accurately decomposed into components, and consists of only Si-db, P b0 and P b1 lines.…”