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Change in morphology and dislocation Etch Pits on the (010) Surface of Magnesium Orthosilicate Crystals
Author(s) -
Desai C. C.,
John V.
Publication year - 1979
Publication title -
kristall und technik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0023-4753
DOI - 10.1002/crat.19790140704
Subject(s) - hydrochloric acid , magnesium , morphology (biology) , dislocation , etching (microfabrication) , potassium , materials science , orthosilicate , potassium hydroxide , sodium , crystallography , chemical engineering , mineralogy , chemistry , inorganic chemistry , metallurgy , composite material , tetraethyl orthosilicate , geology , organic chemistry , nanotechnology , layer (electronics) , paleontology , engineering
Investigations made on the etching behaviour of magnesium orthosilicate crystals in hydrochloric acid and melts of potassium and sodium hydroxides are described. It is shown that the morphology and orientation of the etch pits depend upon the concentration, composition and temperature of the etchant used. At low concentrations of HCl acid solution, the boat shaped pits produced are oriented along [100] direction while in concentrated acid, the hexagonal pits produced are oriented along [001] direction. At intermediate concentrations of about 5 N HCl acid the pits are square. KOH melt at 400 °C is found to produce rectangular pits with their longer sides parallel to [100] direction. The effect of a mixture of KOH and NaOH in different proportions in the melt is investigated. It is observed that square pits are obtained in melt of the mixture of KOH and NaOH in the proportion of 6:4 respectively. The mechanism responsible for the change in orientation of etch pits have been explained. The implications are discussed.