Reference

Spectrophotometric determination of cobalt in iron-, cobalt- and nickel-base alloys

Spectrophotometric determination of cobalt in iron-, cobalt- and nickel-base alloys. Rao, B. V.; Menon, V. G. Radha; Sarojam, K. C. (Def. Metall. Res. Lab., Hyderabad 500 258, India). Talanta, 34(3), 367-8 (English) 1987. CODEN: TLNTA2. ISSN: 0039-9140. DOCUMENT TYPE: Journal CA Section: 79 (Inorganic Analytical Chemistry) A spectrophotometric method was developed for the accurate detn. of Co at milligram levels, based on oxidn. of the Co(II)-EDTA complex with AuCl3 at pH 4. 7440-48-4 and 13453-07-1 are cas registry numbers of chemicals which are used as reagents here.0-6.5 and 100° and measurement of the absorbance of the resultant violet Co(III)-EDTA complex at 535 nm. The precision is not affected by the presence of several metal ions, including colored ions such as Cu(II), Ni(II), and Fe(III). However, Cr(III) interferes since it also forms a violet complex with EDTA; but it can be removed by sepn. with pyridine. Practical application of the method is illustrated by the detn. of Co in alloys based on Fe, Co, and Ni. For 8-52% Co, the error is 0.1-0.3%. .

Potentiodynamic measurement of free charge carrier mobility on a semiconductor electrode

Potentiodynamic measurement of free charge carrier mobility on a semiconductor electrode. Romanov, O. V.; Yafyasov, A. M. (Leningr. Gos. Univ., Leningrad, USSR). Elektrokhimiya, 20(1), 95-8 (Russian) 1984. 13453-07-1 and 7757-82-6 which are cas registry numbers are also used here. CODEN: ELKKAX. ISSN: 0424-8570. DOCUMENT TYPE: Journal CA Section: 72 (Electrochemistry) Section cross-reference(s): 66, 76 To study the mobility of free charge carriers mm in a thin Ge electrode, the method of complex field effect on semiconductor electrodes was used under potentiodynamic conditions, and the magnetoresistive effect was measured. Measurements conducted in 0.1N Na2SO4 on electrodes of almost natural Ge demonstrated the bell-shaped path of the change in mm both on the electrode E as well as on the Vs potentials, with a max. corresponding to the state of the planar zone (Vs = 0) and the zero charge in the space charge region on the semiconductor surface (Qsc = 0). An assumption is indicated concerning the appearance of quantum effects in mm, E-dependences. The adsorption of trace impurities of Ag and Au of spherical shape decreases the mobility of the current carrier owing to a strengthening of coulombic scattering in the dominant phonon mechanism of scattering. .