Cathodoluminescence in deformed MgO crystals

Triboplasma Generation and Triboluminescence: Influence of Stationary Sliding Partner

“…In the near IR region, they further observed a broad CL band consisting of a number of unresolved peaks in the wavelength range 650-830 nm in the undeformed MgO, the strongest which was at 726 nm due to Fe impurities [50]. As the present MgO specimen should have contained the deformed defects on the surface due to the mechanical surface finishing and wear and contained the Fe impurities in 140 ppm as described above, these reports strongly suggest that the two kinds of pair points across the frictional track seen in Fig.…”

Investigating the optical properties of dislocations by scanning transmission electron microscopy

“…In this case, when viewed with band edge or near band edge emission, dislocations are seen dark if they act as nonradiative recombination centers or emit at wavelengths outside the range of detection. However, as has long been known, dislocations can also emit visible light at energies below the band gap (Datta et al 1979;Kiflawi and Lang 1976;Myhajlenko et al 1984;Piqueras et al 1981). A particularly striking example of this effect is shown in Figure 1, where a line of hardness indents have been introduced into a MgO crystal, which was then cleaved so as to reveal the deformed region on two perpendicular surfaces (Pennycook 1978).…”

SEM analyses of cathodoluminescence in MgO, CdS and GaAs/GaxAl1–xAs crystals

“…Our earlier observations (Datta et al, 1979) showed that undeformed MgO has a CL spectrum containing two overlapping blue bands with peaks at 425 nm (2.92 eV) and 488 nm (2.54 eV) and a broad red band containing a number of unresolved peaks, the strongest of which is at about 770 nm (1-61 eV). After deformation, the red band, which is thought to be due to iron impurities, is unaffected and monochromatic red CL micrographs still show a homogeneous emission distribution.…”