1253
Experimental KzC03, I t k ) 2 C ' 0 3 , CsN03, TazOs, and WOa used in
Table I : Compwisori of 13.l3.T.Surface Areiis to Those I>erived from V / n -1)escription-fathoms
surface area, rn.2/g. Iray
Green Green
N 2
Deviation
2.4 10.9 13.4 20.1 43.5 45.3
o/o
11.6
2.3 3.0 0.7 0 8 0.8
The results of this investigation substantiate the use of V / n values in determining surface areas of marine sediments.
Acknowledgment. This work was partially supported by Kational Science I'oundation grant G.1'.622.
Tantalum Substitution in the Hexagonal Tungsten Bronzes
by Ih-ancis Galasso aiid Wilda Darby Uniled Aircraft Corporation IZesearch Laboratories, (Receired .Yovembw 19, 196.9)
these preparations were reagent grade chemicals. Sarnples were prepared hy mixing the constituent powders in appropriate proportions to give products having the general formula A0.3('r&.3W0.7)O3, A = K, ltb, or Cs. The mixture was fired in aluniina cornbustion boats a t 1100" for 24 hr. I'owder X-ray photographs were taken of the products using a I'hilips 57.3rnm. radius camera. High intensity copper K a radiation was used with settings of 40 kv. 30 ma. for 4 hr. High temperature X-ray diffractometcr tracings were niade up to 1000" using a Norclco diffractorncter with an attached HX-2A furnace made by Teiii-Pres h e . These studies wore carried out in air with 110 evidence of sample decomposition. Samples of the phases were analyzed by Ledoux & Company of Teancck, N. J. The analyses corifiriricd that the amount of tantalum ion substituted in each phase correspoiidcd to the general forniula A0.3(Ta0.JWo,7)O:j. Anal. Calcd. for K0.3(Ta0.3W0.7)03:K , 4.83; Ta, 22.36; W, 53.03. Found: I
