Barium fluoride

INTRODUCTION This data sheet provides information for synthetic single crystal barium fluoride. 

Smakula, etal., Harshaw Optical Crystals , Harshaw Chemical Co., Cleveland, (1967). 

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Another use for cryoHte is in the production of pure metal by electrolytic refining. A high density electrolyte capable of floating Hquid aluminum is needed, and compositions are used containing cryoHte with barium fluoride to raise the density, and aluminum fluoride to raise the current efficiency. 

Barium fluoride [7782-32-8] Bap2, is a white crystal or powder. Under the microscope crystals may be clear and colorless. Reported melting points vary from 1290 (1) to 1355°C (2), including values of 1301 (3) and 1353°C (4). Differences may result from impurities, reaction with containers, or inaccurate temperature measurements. The heat of fusion is 28 kj/mol (6.8 kcal/mol) (5), the boiling point 2260°C (6), and the density 4.9 g/cm. The solubiUty in water is about 1.6 g/L at 25°C and 5.6 g/100 g (7) in anhydrous hydrogen fluoride. Several preparations for barium fluoride have been reported (8—10). 

Barium fluoride is used commercially in combination with other fluorides for arc welding (qv) electrode fluxes. However, this usage is limited because of the availabiUty of the much less expensive naturally occurring calcium fluoride. 

Radiopaque materials are used to determine the location of aspirated dentures and fragments (205,206). Opacifying additives include barium sulfate, barium fluoride, barium or bismuth glasses, and brominated organic monomers and polymers. The incorporation of these additives into the resin base or tooth can adversely affect physical properties. Radiopaque materials meeting the requirement for ANSI/ADA specifications for denture-base polymer have been described (207). 

Fluor-, of or combined with fluorine, fluoro-, fluo-, fluoride of (see instances following),. ammonium, n. ammonium fluoride, -an-thenchinon, n. fluoranthenequinone. -anti-mon, n. antimony fluoride, -arson, n. arsenic fluoride, -baryum, n. barium fluoride, -benzol, n. fluorobensene, fluobenaene. -bor, n. boron fluoride. -borsMure, /. fluo-boric acid. -brom, n. bromine fluoride, -chrom, n. chromium fluoride, -eisen, n. iron fluoride. 

Barium fluoride, BaF2, is used in metallurgy as a welding and soldering agent Its Kw is 1.8 X 10 7. 

Strategy lb relate s to Kspt start by writing the equation for dissolving barium fluoride in water ... 

Barium, 543 Barium fluoride, 435 Barium hydroxide, 357-358 Barlett, Neil, 100 Barometer, 104... 

Goldschmidt predicted from his empirical rule that calcium chloride would not have the fluorite structure, and he states that on investigation he has actually found it not to crystallize in the cubic system. Our theoretical deduction of the transition radius ratio allows us to predict that of the halides of magnesium, calcium, strontium and barium only calcium fluoride, strontium fluoride and chloride, and barium fluoride, chloride,... 

Direct visualization of femtosecond filamentation is crucial to understanding the phenomenon. As the energy of a single infrared photon is much too small to effect an electronic transition, one has to take recourse to multiphoton absorption induced fluorescence to come up with a scheme to directly visualize filamentation in condensed media. One such scheme that has been successfully implemented involves the use of a crystal of barium fluoride, a material that is known to be very good scintillator [38]. 

Figure 5.2 shows that the onset of collapse in barium fluoride as the incident power is varied from 110 PCT to 1,200 Pcr. The onset of filamentation, z0f, the filament start position (the arrow in each panel marks the onset position), varies from 4.6 mm inside the crystal at 110 PCI to a position that is located on the incident face of the crystal at 1,200 PCI. Note that the images in Fig. 5.2 indicate that multiple filamentation occurs within the crystal at such high power levels. 

To optimize the conversion efficiency, physical focusing conditions need to be optimized. With reference to the SG spectrum shown in Fig. 5.8, for fixed incident laser power and fixed focal length of the lens, the location of the focus point within the 7.5 cm long barium fluoride crystal was found to determine the extent of the white light spectrum. With the focus located f cm inside the crystal, the flattest possible spectrum of white light was obtained (as shown in Fig. 5.8), and the highest conversion efficiency was also achieved. 

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