Delineation of defect structures in flux-grown GdFeO3 crystals by etching

Etch patterns on (<(11)over bar 0>) and (001) faces of as-obtained GdFeO3 crystals are illustrated and described. Rectangular etch pits oriented with their longer sides in [100] direction and shorter sides in [010] direction are exhibited by [001] faces, whereas almost circular etch pits are exhibited by (<(11)over bar 0>) faces of as-obtained crystals. Hexagonal etch pits and triangular etch pits produced as a result of etching in boiling HNO3 on (001) and (<(11)over bar 0>) faces are respectively illustrated. Evidence in support of twinning in some crystals is offered. The etch pattern on as-grown crystals are attributed to some fault in their growth conditions. Edge nucleated growth pyramids on a (<(11)over bar 0>) face and conical hillocks on (001) faces exhibiting pits at the centres of their initiation are illustrated. The conical hillocks are suggested to be as a result of preferential growth at the point of emergence of screw dislocations. (C) 2000 Elsevier Science B.V. All rights reserved.