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Recent Developments in the Chemical Thermodynamics of the Uranium Chalcogenides; Progres Accomplis Recemment dans la Thermodynamique Chimique des Chalcogenures d'Uranium; Poslednie dostizheniya v khimicheskoj termodinamike khal'kogenidov Urana; Recientes Progresos en la Termodinamica Quimica de los Calcogenidos de Uranio

Conference:

Abstract

Extension of the cryothermal data on tetrauranium enneaoxide to higher temperatures has revealed the thermophysical aspects of the (suspected) gradual, {lambda}-type, structural transition at 348 Degree-Sign K with an associated entropy increment of 1.84 cal/gfm Degree-Sign K involved in the displacement of interstitial oxygen atoms. Measurements of both heat capacity and magnetic susceptibility on Mallinckrodt sintered uranium dioxide have confirmed that the antiferromagnetic-paramagnetic transition occurs at 30.4 Degree-Sign K with a heat capacity of 400 cal/gfm Degree-Sign K rather than at 28.7 Degree-Sign K with 9 cal/gfm Degree-Sign K as reported in the literature. This now permits interpretation of the thermal anomaly found in {beta}-triuranium heptaoxide. Cryogenic heat capacities on well-characterized samples of {alpha}-, {beta}- and {gamma}-uranium trioxide prepared by Dr. E.H.P. Cordfunke of Reactor Centrum Nederland are combined with his higher temperature heat capacities, enthalpies of formation and other thermodynamic data to yield relative stability data for these important nuclear materials. Both uranium monoselenide and Uranium diselenide are found to have lambda-type anomalies associated with magnetic disordering. That in uranium diselenide occurs at 13.1 Degree-Sign K with an associated entropy increment of 0.16 cal/gfm Degree-Sign K. The 160 Degree-Sign K anomaly in the monoselenide has an entropy increment of  More>>
Authors:
Westrum, Jr., E. F. [1] 
  1. University of Michigan, Ann Arbor, MI (United States)
Publication Date:
Feb 15, 1966
Product Type:
Conference
Report Number:
IAEA-SM-66/2
Resource Relation:
Conference: Symposium on Thermodynamics with Emphasis on Nuclear Materials and Atomic Transport in Solids, Vienna (Austria), 22-27 Jul 1965; Other Information: 36 refs., 1 tab., 6 figs.; Related Information: In: Thermodynamics. Vol. II. Proceedings of the Symposium on Thermodynamics with Emphasis on Nuclear Materials and Atomic Transport in Solids| 673 p.
Subject:
36 MATERIALS SCIENCE; ANTIFERROMAGNETISM; ENTROPY; FORMATION HEAT; MAGNETIC SUSCEPTIBILITY; OXYGEN; PARAMAGNETISM; SPECIFIC HEAT; TEMPERATURE RANGE 0400-1000 K; THERMODYNAMICS; URANIUM DIOXIDE; URANIUM SELENIDES; URANIUM TRIOXIDE; URANIUM-ALPHA; URANIUM-BETA; URANIUM-GAMMA
OSTI ID:
22127271
Research Organizations:
International Atomic Energy Agency, Vienna (Austria); International Union of Pure and Applied Chemistry, Commission on Thermodynamics and Thermochemistry, Research Triangle Park, NC (United States)
Country of Origin:
IAEA
Language:
English
Other Identifying Numbers:
Other: ISSN 0074-1884; TRN: XA13M2422082350
Submitting Site:
INIS
Size:
page(s) 497-510
Announcement Date:
Sep 12, 2013

Conference:

Citation Formats

Westrum, Jr., E. F. Recent Developments in the Chemical Thermodynamics of the Uranium Chalcogenides; Progres Accomplis Recemment dans la Thermodynamique Chimique des Chalcogenures d'Uranium; Poslednie dostizheniya v khimicheskoj termodinamike khal'kogenidov Urana; Recientes Progresos en la Termodinamica Quimica de los Calcogenidos de Uranio. IAEA: N. p., 1966. Web.
Westrum, Jr., E. F. Recent Developments in the Chemical Thermodynamics of the Uranium Chalcogenides; Progres Accomplis Recemment dans la Thermodynamique Chimique des Chalcogenures d'Uranium; Poslednie dostizheniya v khimicheskoj termodinamike khal'kogenidov Urana; Recientes Progresos en la Termodinamica Quimica de los Calcogenidos de Uranio. IAEA.
Westrum, Jr., E. F. 1966. "Recent Developments in the Chemical Thermodynamics of the Uranium Chalcogenides; Progres Accomplis Recemment dans la Thermodynamique Chimique des Chalcogenures d'Uranium; Poslednie dostizheniya v khimicheskoj termodinamike khal'kogenidov Urana; Recientes Progresos en la Termodinamica Quimica de los Calcogenidos de Uranio." IAEA.
@misc{etde_22127271,
title = {Recent Developments in the Chemical Thermodynamics of the Uranium Chalcogenides; Progres Accomplis Recemment dans la Thermodynamique Chimique des Chalcogenures d'Uranium; Poslednie dostizheniya v khimicheskoj termodinamike khal'kogenidov Urana; Recientes Progresos en la Termodinamica Quimica de los Calcogenidos de Uranio}
author = {Westrum, Jr., E. F.}
abstractNote = {Extension of the cryothermal data on tetrauranium enneaoxide to higher temperatures has revealed the thermophysical aspects of the (suspected) gradual, {lambda}-type, structural transition at 348 Degree-Sign K with an associated entropy increment of 1.84 cal/gfm Degree-Sign K involved in the displacement of interstitial oxygen atoms. Measurements of both heat capacity and magnetic susceptibility on Mallinckrodt sintered uranium dioxide have confirmed that the antiferromagnetic-paramagnetic transition occurs at 30.4 Degree-Sign K with a heat capacity of 400 cal/gfm Degree-Sign K rather than at 28.7 Degree-Sign K with 9 cal/gfm Degree-Sign K as reported in the literature. This now permits interpretation of the thermal anomaly found in {beta}-triuranium heptaoxide. Cryogenic heat capacities on well-characterized samples of {alpha}-, {beta}- and {gamma}-uranium trioxide prepared by Dr. E.H.P. Cordfunke of Reactor Centrum Nederland are combined with his higher temperature heat capacities, enthalpies of formation and other thermodynamic data to yield relative stability data for these important nuclear materials. Both uranium monoselenide and Uranium diselenide are found to have lambda-type anomalies associated with magnetic disordering. That in uranium diselenide occurs at 13.1 Degree-Sign K with an associated entropy increment of 0.16 cal/gfm Degree-Sign K. The 160 Degree-Sign K anomaly in the monoselenide has an entropy increment of 1.0 cal/gfm Degree-Sign K, which may be compared with the value of 1.17 found for the monosulfide near 180 Degree-Sign K. Both thermal anomalies in the monochalcogenides arise as a consequence of disordering the ferromagnetic state and contrast with the antiferromagnetic anomaly found in the isostructural mononitride at 52 Degree-Sign K. The new thermodynamic data accord well with the entropy estimation scheme of Gronvold and Westrum. (author) [French] L'extension de la temperature plus elevee des valeurs aux basses temperatures des constantes relatives au nonaoxyde de tetrauranium a revele les aspects thermophysiques de la transition structurale de ' type {lambda} supposee progressive a 348 Degree-Sign K avec accroissement d'entropie associe de 1,84 cal/gfm Degree-Sign K, qui intervient dans le deplacement d'atomes d'oxygene interstitiels. Des mesures de la capacite calorifique et de la susceptibilite magnetique sur du bioxyde d'uranium fritte de Mallincktodt ont confirme que la transition antiferromagnetique-paramagnetique se produit a 30,4 Degree-Sign K avec 400 cal/gfm Degree-Sign K pour la capacite calorifique et non a 28,7 Degree-Sign K avec une saute de 9 cal/gfm Degree-Sign K comme il est dit dans d'autres ouvrages. On peut ainsi interpreter l'anomalie thermique trouvee dans l'heptaoxyde de triuianium beta. L'auteur a combine les capacites calorifiques, aux basses temperatures, d'echantillons bien caracterises de trioxyde d'uranium alpha, beta et gamma prepares par E. Cordfunke du Reactor Centrum Nederland avec les valeurs des capacites calorifiques, des enthalpies de formation et d'autres constantes thermodynamiques pour en tirer les valeurs de la stabilite relative pour ces importants materiaux nucleaires. Il a constate que le mohoseleniure et le biseleniure d'uranium presentaient tous deux des anomalies du type lambda associees a un desordre magnetique. Cette anomalie se produit a 13,1 Degree-Sign K dans le biseleniure, avec un accroissement d'entropie associe de 0,16 cal/gfm Degree-Sign K. L'anomalie se produisant a 160 Degree-Sign K dans le monoseleniure est accompagnee d'un accroissement d'entropie de 1,0 cal/gfm Degree-Sign K, qui peut etre compare a la valeur 1,17 trouvee pour le monosulfure au voisinage de 180 Degree-Sign K. Les deux anomalies thermiques dans les monochalcogenures resultent d'un desordre de l'etat ferromagnetique et s'opposent b l'anomalie antiferromagnetique constatee dans le mononitrure isostructural a 52 Degree-Sign K. Les nouvelles valeurs des constantes thermodynamiques sont en bon accord avec le systeme d'estimation de l'entropie de Gronvold et Westrum. (author) [Spanish] La extension a temperaturas mas elevadas de los datos criotermicos correspondientes al U{sub 4}O{sub 11} ha puesto de manifiesto los aspectos termoffsicos de la transicion estructural gradual (sospechada) de tipo lambda a 348 Degree-Sign K, con un correspondiente aumento de entropia igual a 1,84 cal/gfm Degree-Sign K, vinculado al desplazamiento de atomos de oxigeno intersticiales. Las mediciones, de la capacidad calorifica y de la susceptibilidad magnetica, realizadas con UO{sub 2}'Mallinckrodt' sinterizado, confirmaron que la transicion antiferromagnetica-paramagnetica tiene lugar a 30,4 Degree-Sign K con una variacion de capacidad calorifica igual a 400 cal/gfm Degree-Sign K, en lugar de producirse a 28,7eK con una variacion de 9 cal/gfm eK, segun se informa en la literatura tecnica. Con ello se puede interpretar ahora la anomalia termica hallada en el U{sub 3}O{sub 7}-{beta}. La capacidad calorifica a bajas temperaturas de muestras bien caracterizadas de UO{sub 3}-{alpha}, UO{sub 3}-{beta} y UO{sub 3} -{gamma}, preparadas por el Dr. E.H.P. Cordfunke, del Reactor Centrum Nederland, se combina con estas capacidades calorificas a temperaturas mas elevadas, con las entalpias de formacion y con otros datos termodinamicos, para obtener datos de estabilidad relativa correspondientes a esos importantes materiales nucleares. Tanto el monoseleniuro como el diseleniuro de uranio poseen anomalias de tipo lambda vinculadas al desordenamiento magnetico. La del diseleniuro de uranio se produce a 13,1 Degree-Sign K, con un incremento de entropia igual a 0,16 cal/gfm Degree-Sign K. La anomalia de 160 Degree-Sign K tiene un incremento de entropia de 1,0 cal/gfm eK, que puede compararse con el valor 1,17 encontrado para el monosulfuro cerca de los 180 Degree-Sign K. Ambas anomalias termicas observadas en los monocalcogenidos surgen como consecuencia del desordenamiento del estado ferromagnetico y contrastan con la anomalia antiferro- magnetica hallada en el mononitruro isoestructural a 52 Degree-Sign K. Los nuevos datos termodinamicos concuerdan satisfactoriamente con los obtenidos mediante el procedimiento de evaluacion de entropia de Gronvold y Westrum. (author) [Russian] Rasprostranenie kriotermicheskih dannyh no U{sub 4}O{sub 9} na bolee vysokie temperatury pokazalo termofizicheskie aspekty (predpolagaemogo) postepennogo strukturnogo prevrashhenija tipa-A. pri temperature 348 Degree-Sign K s sootvetstvujushhim prirashheniem jentropii v razmere 1,84 kalorij/gramm-mol' OK, svjazannogo so smeshheniem vnedrennyh atomov kisloroda. Izmerenija kak teploemkosti, tak i magnitnoj vospriimchivosti na spechennoj dvuokisi urana Mol- linkrodta podtverdili, chto antiferromagnitnyj-paramagnitnyj perehod proishodit pri 30,4 Degree-Sign K so skachkom teploemkosti v 400 kalorij/gramm-mol' Degree-Sign K, a ne pri 28,7 Degree-Sign K s povysheniem teploemkosti na devjat' kalorij/gramm-mol' Degree-Sign K, kak soobshhalos' v literature. Jeto pozvoljaet teper' ob{sup j}asnit' termicheskuju anomaliju, obnaruzhennuju v {beta} -U{sub 3}O{sub 7}. Kriogennye teploemkosti, poluchennye na harakternyh obrazcah {alpha}-, {beta}-, i {gamma} utriokisi urana, podgotovlennyh doktorom E.G.P.Kordfunke iz Niderlandskogo reaktornogo centra, kombinirujutsja s teploemkostjami pri bolee vysokoj temperature, jental'pijami obrazovanija i drugimi termodinamicheskimi dannymi dlja poluchenija dannyh ob otnositel'noj stabil'nosti jetih vazhnyh jadernyh materialov. Obnaruzheno, chto kak monoselenid urana, tak i diselenid urana imejut anomalii tipa ljambda, svjazannye s magnitnym razuporjadocheniem. V diselenide urana jeto proishodit pri 13,1 Degree-Sign K s prirashheniem jentropii v 0,16 kalorij/gramm-mol' Degree-Sign K. Prirashhenie jentropii v monoselenide pri anomalii pri 160 Degree-Sign K sostavljaet velichinu 1,0 kalorij/gramm- mol' Degree-Sign K, chto mozhno sravnit' s velichinoj 1,17, poluchennoj dlja monosul'fida pri temperature okolo 180 Degree-Sign K. Obe termicheskie anomalii v monohal'kogenidah voznikajut vsledstvie razupo- rjadochenija ferromagnitnogo sostojanija i otlichajutsja ot antiferromagnitnoj anomalii, obnaruzhennoj v izostrukturnom mononitride pri temperature 52 Degree-Sign K. Novye termodinamicheskie dannye horosho soglasujutsja so shemoj ocenki jentropii Gronvold i Westrum. (author)}
place = {IAEA}
year = {1966}
month = {Feb}
}