process for zuechten ions doped single crystals of paramagnetischen from wolframaten the erdalkalimetalle calcium, strontium or barium

摘要

In pulling from a melt a single crystal of calcium, strontium or barium tungstate containing 0.01-15 atom per cent of trivalent rare earth metal ions, the melt contains at least 1.5 sodium, potassium or lithium ions per trivalent ion and up to 30 atom per cent thereof (based on divalent ions). The rare earth metal may be neodymium, cerium or thulium. The mono-, di-, and trivalent metal tungstates may be formed by the reaction of oxide, nitrate or carbonate with tungstic acid anhydride.ALSO:In pulling from a melt a single crystal of calcium, strontium or barium tungstate containing 0.01-15 atom per cent of trivalent rare earth metal ions, the melt contains at least 1.5 sodium, potassium or lithium ions per trivalent ion and up to 30 atom per cent thereof (based on divalent ions). The rare earth metal may be neodymium, cerium or thulium. The mono-di-, and tri-valent metal tungstates may be formed by the reaction of oxide, nitrate or carbonate with tungstic acid anhydride. The metal temperature may be 1525-1625 DEG C. The crucible may be of rhodium or iridium. The crystal may be pulled at 0.5 in/hr and rotated at 60 rpm. Pulling may be in an inert or oxygen-containing atmos.