The Radiochemistry of the Rare Earths, Scandium, Yttrium, and Actinium

Stevenson, P.C.; Nervik, W.E.

doi:10.2172/4061656

Cited by 70 publications

(37 citation statements)

References 21 publications

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“…However, the procedures are time consuming and require much skill for analytical chemistry because of extremely small differences in the chemical properties between gadolinium and other trivalent lanthanides. Fortunately, europium can be reduced to a fairly stable Eu (II) ion, whose chemical behaviour is similar to alkaline earth elements [2]. Therefore, europium may be separated…”

Section: Discussionmentioning

confidence: 99%

Zur Kristallchemie des Radiums

Weigel

Trinkl

1968

Radiochimica Acta

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allowing simple analytical fluorine determination by direct titration or PbCIF precipitation. The low boiling point of trimethylfluorosilane (16.4 °C) was expected to be troublesome, but it was found that trimethylfluorosilane solutions in benzene are very stable even on heating to 80 °C, probably because of the formation of π-complexes. The fluorine yields obtained after radiochemical purification by CaS04 separation and subsequent NH4F sublimation varied between 40 and 60%. The radiochemical purity of 18 F was very good (i1/2 = 110 + 2 min.). Sublimation alone is quite efficient for separating 18 F from all activities except CI, which apparently cosublimes to a small extent. Cosublima-tion with NH4C1 provides a method for preparing carrier-free 18 F. The sublimation method is very simple and many fluorine samples can be handled at the same time. The fluorine yields determined by either titration with the fluorine ion specific electrode or the. PcCIF method agreed well with each other. AcknowledgementWe are indebted to the staffs of the NRL linear accelerator and reactor for performing many irradiations. The trimethylchlorosilane was generously provided by the General Electric Company. We thank Earl DAVIS for technical assistance. ZusammenfassungMetallisches Radium wurde im Mikromaßstab durch Reduktion von Radiumoxid mit Aluminium im Hochvakuum dargestellt und direkt in eine Röntgenkapillare einsublimiert. Die röntgenographische Untersuchung so erhaltener Radiummetallspiegel ergab, daß Radium kubisch-raumzentriert mit einer Gitterkonstante a0 = 5,148 ± 0,015 À, Raumgruppe 0h -Im 3 m, isotyp mit Bariummetall kristallisiert. Die röntgenographische Dichte bei 2 Atomen in der Elementarzelle ergab sich zu S,50 gern -3 , woraus sich das Atemvolumen zu 40,92 cm 3 berechnet. Bei einer Koordinationszahl 8 beträgt der Atomradius 2,23 ± 0,01 Â. Normierung auf die Koordinationszahl 12 lieferte einen korrigierten Atomradius von 2,32 ± 0,02 Â. Das System der Actinidenmetallradien von ZACHARIASEN, CUNNINGHAM und WALLMANN wird unter Verwendung von Radium als Bezugselement revidiert. SummaryMetallic radium was prepared on the microgram scale by reduction of radium oxide with aluminum in a high vacuum. The metal was sublimed directly into an X-ray capillary. Prom X-ray studies on radium metal mirrors obtained by this method, it was found that radium has a bcc structure with a0 = 5.148 ± 0.015Á, space group Oh -Im3 m, and that t is isomorphous with barium metal. The X-ray density for Ν = 2 atoms in the unit cell is calculated to be 5.50 gem -3 . From this value, an atomic volume of 40.92 cm 3 is derived. For coordination number 8, the atomic radius is found to be 2.23 ± 0.01 Â, stadardization for coordination number 12 yields a value of 2.32 ± 0.02 À for the corrected radius. The system of actinide metal radii derived by ZACHARIASEN, CUNNINGHAM and WALLMANN is revised using radium as the reference standard. RésuméOn prépare du radium métallique à l'échelle du microgramme par réduction de l'oxyde de radium par l'aluminium sous vide...

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Section: Discussionmentioning

confidence: 99%

Zur Kristallchemie des Radiums

Weigel

Trinkl

1968

Radiochimica Acta

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“…aluminum absorber to block all the beta emission from both cerium-141 and -144 and count only the hard 2.98-m.e.v. emission of the praseodymium-144 daughter (3, 9). About 2 to 3 hours should be allowred before counting to permit complete ingrowth of the 17.5minute praseodymium-144.…”

Section: Separation Of Ceriummentioning

confidence: 99%

Determination of Radioisotopes of Cerium, Barium, Lanthanum, and Neptunium after Separation by Barium Sulfate.

Sill¹,

Willis²

1966

Anal. Chem.

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“…2). Ranges for both variables were chosen to encompass the conditions of previous works cited from the literature [2][3][4][6][7][8][9][10][11][12][13][14]. Separation resolutions were calculated from peak RTs and widths reported directly from the Chormeleon software package provided by Dionex.…”

Section: Methodsmentioning

confidence: 99%

“…However, due to their similar size and charge (all predominantly reside in the +III oxidation state), all of the elements within the Ln series, especially nearest neighboring Lns, exhibit relatively similar chemistry, so separating mixtures of these elements is a formidable task. In the past, a number of techniques have been used to effect the separation of individual Ln elements and reviews of these techniques are available from the literature [2,3]. To this end, cation exchange chromatography using alpha-hydroxyisobuturic acid (␣-HIB) is widely considered to be the most effective methods for separating these elements.…”

Section: Introductionmentioning

confidence: 99%