Experimental investigation of the Cd-Pr phase diagram.
The complete Cd-Pr equilibrium phase diagram was investigated with a combination of powder-XRD, SEM and DTA. All intermetallic compounds within this system, already reported in literature, could be confirmed: CdPr, Cd2Pr, Cd3Pr, Cd45Pr11, Cd58Pr13, Cd6Pr and Cd11Pr. The corresponding phase boundaries were determined at distinct temperatures. The homogeneity range of the high-temperature allotropic modification of Pr could be determined precisely and a limited solubility of 22.1 at.% Cd was derived. Additionally, single-crystal X-ray diffraction was employed to investigate structural details of Cd2Pr; it is isotypic to the AlB2-type structure with a z value of the Cd site of 0.5. DTA results of alloys located in the adjacent two-phase fields of Cd2Pr suggested a phase transformation between 893 and 930°C. For the phase Cd3Pr it was found that the lattice parameter a changes linearly with increasing Cd content, following Vegard's rule. The corresponding defect mechanism could be evaluated from structural data collected with single-crystal XRD. Introduction of a significant amount of vacancies on the Pr site and the reduction in symmetry of one Cd position (8c to 32f) resulted in a noticeable decrease of all R-values.
Department of Inorganic Chemistry (Materials Chemistry), University of Vienna, Wien, Austria.
Thomas L
TL
Reichmann
Department of Mineralogy and Crystallography, University of Vienna, Wien, Austria.
Herta S
HS
Effenberger
Department of Inorganic Chemistry (Materials Chemistry), University of Vienna, Wien, Austria.
Herbert
H
Ipser
D000497:Alloys / Q000737:chemistry; D002104:Cadmium / Q000737:chemistry*; D019187:Cadmium Compounds / Q000737:chemistry; D018360:Crystallography, X-Ray; D004055:Differential Thermal Analysis; D059625:Liquid-Liquid Extraction; D008956:Models, Chemical; D009678:Nuclear Energy; D044367:Phase Transition; D011221:Praseodymium / Q000737:chemistry / Q000302:isolation & purification*; D011850:Radioactive Waste; D012995:Solubility; D013696:Temperature; D013816:Thermodynamics; D044366:Transition Temperature
D000497:Alloys; D019187:Cadmium Compounds; D011850:Radioactive Waste; D002104:Cadmium; D011221:Praseodymium