Transmission electron microscopy of defect cascades in YBa₂Cu₃O_7−δproduced by ion irradiation

A route for a strong increase of critical current in nanostrained iron-based superconductors

“…We note that besides the clearly visible cascade, there is also a curvature of the lattice fringe inwardly directed, which produces strain field around the cascade defect. Similar strain fields created by low-energy proton and neutron irradiation were observed in YBCO single crystals from a previous TEM study5152. Although the size of the cascade defects is about 1∼2 nm in diameter and ∼10 nm wide, the strain fields are expected to extend far out to the cascade defect, especially in the radial direction and, as a result, can cause the local lattice distortion.…”

Strain field and strain contrast of columnar defects in heavy-ion irradiated superconductors

“…2 ( d ) ) that causes matrix atoms to be displaced radially outward. However, the 'interstitial' type of strain field in our samples irradiated with 300 MeV Au-ions differs from the 'vacancy' type of strain field observed by Frischherz, Kirk, Zhang and Weber (1993) in YBa,Cu,O,-, irradiated with 50 keV Kr ions. Such a difference in the characteristics of the defect may be attributed to the large difference in energy of the incident ions.…”

Transmission electron microscopy study of ion-beaminduced amorphization of Ca2La8(SiO4)6O2

“…Consequently, we cannot rule out the possibility that the formation of amorphous regions may require cascade overlap based on the plan-view HRTEM study. However, direct impact amorphization in Ca2La8 (Si04)602 seems plausible based on the complexity of the crystal structure and the results of previous studies , Frischherz et al 1993). …”