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[en] The formation of thorium molybdates obtained by interaction of thorium nitrate and sodium molybdate at specific pH levels 7.8 and 4.1 have been studied by electrometric techniques involving pH and conductometric titrations. The well defined inflections in titration curves provide cogent evidence for the formation of thorium normal ThO₂.2MoO₃ and para-3ThO₂. 14 MoO₃ molybdates in the vicinity of pH 5.3 and 4.1 respectively. Analytical investigations support the electrometric results. (author)

[en] An accurate and rapid electrometric method for the determination of praseodymium and thorium as their meta-arsenates has been investigated. It consists in titrating praseodymium chloride and thorium nitrate solutions pH-metrically against a standard solution of sodium meta-arsenate, using a wide range glass electrode in conjunction with S.C.E. A marked change in pH is observed at the end-point corresponding to the precipitation of Pr(AsO₃)₃ and Th₃(AsO₃)₄ in the neighbourhood of pH 4.8 and 4.2, respectively. The curves have a regular form and a pronounced maximum in dpH/dV occurs at the end-point. The accuracy and reproducibility of the results have been found to be excellent even at low concentrations (5x10sup(-4)M) of the reactants. pH titration offers a simple, rapid and accurate method for the determination of praseodymium and thorium as their meta-arsenates. Similar titrations were also performed for estimation of samarium but they failed to provide any dependable results. (author)

[en] We have studied the Moessbauer and magnetization of melt spun amorphous Fe_74-xAl_xEr₆B₂₀ alloys with 0≤x≤15. Moessbauer studies were carried at room temperature as well as at 80 K. The average hyperfine field values are found to decrease with the Al concentration. Magnetization studies were carried out under magnetic fields up to 140 kOe. The results were analyzed using random magnetic anisotropy model

[en] The formation of thorium molybdates obtained by interaction of thorium nitrate and sodium molybdate at specific pH levels 7.8, 5.5 and 4.1 have been studied by electrometric techniques involving pH and conductometric titrations. The well-defined inflections and breaks in titration curves provide cogent evidence for the formation of thorium normal-Th O₂.2 Mo O₃ and para- e Th O₂.14 Mo O₃ molybdates in the vicinity of pH 5.3 and 4.4, respectively. Analytical investigations on the precipitates of thorium molybdates have also been carried out, which support the electrometric results. (author)

[en] Thin copper ferrite films have been deposited on amorphous quartz substrates. The films are annealed in air and either quenched in liquid nitrogen or slow cooled from the annealing temperature. The quenched as well as slow cooled films, show (1 1 1) peaks of copper ferrite along with the (3 1 1) peak. This indicates strong (1 1 1) orientation of the films. From the MH loops, squareness value (M_R/M_S) has been calculated for both type of films. The squareness value of the parallel MH loop is double the value of the perpendicular MH loop

[en] The precise nature of the polyanions formed by the action of hydrochloric acid on sodium molybdate solutions has been studied by pH and conductometric measurements involving glass electrode and conductometric titrations. The inflections and breaks in the titration curves indicate the formation of para-Mo₇ O₂₄^6- and octa-Mo₈ O₂₄^6- polymolybdate anions around pH5.5 and 4.1, corresponding to the molar ratio 8 H:7 Mo and 3 H:2 Mo, respectively. Similar pH and conductometric titrations between Hg²⁺ and Mo O₄^2-, Mo₇ O₂₄^6-, and Mo₈ O₂₆^4- provide definite evidence for the formation of normal molybdate Hg O. Mo O₃, paramolybdate 3 Hg O.7 Mo O₃ and octamolybdate 2 Hg O.8 Mo O₃ of mercury(II) in the vicinity of the pH 4.9, 4.2 and 3.7, respectively. The analytical investigations of the precipitates of mercuric molybdates have also been carried out, which substantiate the results of the electrometric study. (author)

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