METHOD FOR ETCHING SURFACE OF SUBSTRATE OF RARE EARTH METALLIC PENTAPHOSPHATE

• Main Authors: OOTA KIMIHIRO, OONISHI NORIO
• Format: Patent
• Language: English
• Published: 12.01.1985
• Edition: 4
• Subjects: ARTIFICIAL STONE; BASIC ELECTRIC ELEMENTS; CEMENTS; CERAMICS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; CONCRETE; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; LIME, MAGNESIA; METALLURGY; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLICMATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASSC23 AND AT LEAST ONEPROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25; NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; REFRACTORIES; SEMICONDUCTOR DEVICES; SLAG; TREATMENT OF NATURAL STONE

PURPOSE:To observe crystal defects in a substrate of a rare earth matallic pentaphosphate due to bubbles contained in the substrate by etching technique by bringing the surface of the substrate into contact with H2SO4, K2S2O7 or NH4F. HF at a specified temp. CONSTITUTION:A crystal substrate of NdP5O14, LaP5O14 or other rare earth metallic pentaphosphate is brough into contact with H2SO4 at 120-250 deg.C, K2S2O7 at 210-250 deg.C or NH4F.HF at 110-200 deg.C in a platinum beaker or the like. After a fixed time, the reagent is discharged, and the etched substrate is washed and dried. By this method, sharp etch pits are observed, and the existence of linear defects, etc. reaching bubbles in the crystal is confirmed from the pits.