. Various photo-electrical investigations. ie and Kruyt ^sometimes succeeded in melting and resolidifying stibnite withoutdestroying its photo-electrical sensitivity. They prepared arti-ficial stibnite, sometimes in open tubes (also in evacuated tubes 2 Jaeger, Zs., fiir Kristallographie, 44, p. 45; 1907. Olie and Kruyt, Koninkliike Akademie Von Wetenschoppen, Amsterdam, 14, p. 740; 1912. CMcnl:] Photo-Electrical Investigations. 589 heated to 600° C), and found that the highest photo-electricalsensitivity was obtained when the Sb and S were mixed in exactproportions to give SbjSj. They thought
. Various photo-electrical investigations. ie and Kruyt ^sometimes succeeded in melting and resolidifying stibnite withoutdestroying its photo-electrical sensitivity. They prepared arti-ficial stibnite, sometimes in open tubes (also in evacuated tubes 2 Jaeger, Zs., fiir Kristallographie, 44, p. 45; 1907. Olie and Kruyt, Koninkliike Akademie Von Wetenschoppen, Amsterdam, 14, p. 740; 1912. CMcnl:] Photo-Electrical Investigations. 589 heated to 600° C), and found that the highest photo-electricalsensitivity was obtained when the Sb and S were mixed in exactproportions to give SbjSj. They thought that the photo-electricalsensitivity was affected by the kind of glass tubes used in prepar-ing the material. Using a different kind of glass, they did notobtain a single preparation which was photosensitive. By per-forming the operation in evacuated glass tubes they succeeded inremelting the native (Japanese) stibnite without destroying itsphoto-electrical sensitivity. A loss of per cent of S resultedin a totally inert n .78 Fig. I.—Effect of heating upon ike spectropkoto-electrical sensitivity of stibniie. In the present tests two samples of stibnite which were fotmdsensitive were heated in an electric furnace for one hour at each ofthe following temperatures: 120, 200, 300, and 400° C, afterwhich the samples were cooled and their photosensitivity deter-mined. The average intrinsic photosensitivity (ratio of lightcurrent : dark current) as determined after heating to thesetemperatures did not change systematically in the temperatureinterval up to 400° C. At 500° C. these crystals were completelyoxidized by the long heating. In another test, four samples were heated to 500° C. for a shorttime when they were found to have melted and merged into twolumps, one of which appeared porous and was nonsensitive photo-electrically. The other lump was as photosensitive as the originalunmelted material. On examination under a low-power micro-scope it was foimd th
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Keywords: ., bookauthorcoblentz, bookcentury1900, bookdecade1920, bookyear1922
