Plutonium physical properties

Pu-242 samples are available in enrichments ranging from 99.9+% to 95% production-grade material ranges from 85% to 95%. Uses are for the study of plutonium physical properties and as a mass spectroscopy tracer and standard. 

The chemistry of plutonium is unique in the periodic table. This theme is exemplified throughout much of the research work that is described in this volume. Many of the properties of plutonium cannot be estimated accurately based on experiments with lighter elements, such as uranium and neptunium. Because massive amounts of plutonium have been and are being produced throughout the world, the need to define precisely its chemical and physical properties and to predict its chemical behavior under widely varying conditions will persist. In addition to these needs, there is an intrinsic fundamental interest in an element with so many unusual properties and with so many different oxidation states, each with its own chemistry. 

TaylorDM. 1973. Chemical and physical properties of the transplutonium elements. In Hodge HC, Stannard JN, Hursh JB, eds. Uranium, plutonium, transplutonic elements. New York Springer-Verlag, 717-738. 

Apart from d- and 4f-based magnetic systems, the physical properties of actinides can be classified to be intermediate between the lanthanides and d-electron metals. 5f-electron states form bands whose width lies in between those of d- and 4f-electron states. On the other hand, the spin-orbit interaction increases as a function of atomic number and is the largest for actinides. Therefore, one can see direct similarity between the light actinides, up to plutonium, and the transition metals on one side, and the heavy actinides and 4f elements on the other side. In general, the presence or absence of magnetic order in actinides depends on the shortest distance between 5f atoms (Hill limit). 

All isotopes of plutonium are radioactive. The two isotopes that have found the most uses are Pu-238 and Pu-239. Pu-238 is produced by bombarding U-238 with deuterons in a cyclotron, creating neptunium-238 and two free neutrons. Np-238 has a half-life of about two days, and through beta decay it transmutates into plutonium-238. There are six allotropic metallic crystal forms of plutonium. They all have differing chemical and physical properties. The alpha (a) aUotrope is the only one that exists at normal room temperatures and pressures. The alpha allotrope of metallic plutonium is a silvery color that becomes yellowish as it oxidizes in air. AH the other allotropic forms exist at high temperatures. 

After the discovery of plutoninm and before elements 95 and 96 were discovered, their existence and properties were predicted. Additionally, chemical and physical properties were predicted to be homologous (similar) to europium (gjEu) and gadolinium ( Gd), located in the rare-earth lanthanide series just above americium (gjAm) and curium ((,jCm) on the periodic table. Once discovered, it was determined that curium is a silvery-white, heavy metal that is chemically more reactive than americium with properties similar to uranium and plutonium. Its melting point is 1,345°C, its boihng point is 1,300°C, and its density is 13.51g/cm. ... 

The chemical and physical properties of Unq (or rutherfordium) are homologous with the element hafnium ( jHf), located just above it in group 4 (fVB) in the periodic table. It was first claimed to be produced artificially by the Joint Institute for Nuclear Research (JINR) located in Dubna, Russia. The Russian scientists used a cyclotron that smashed a target of plutonium-242 with very heavy ions of neon-22, resulting in the following reaction Pu-242 + jjjNe-22 —> jj, Unq-260 + 4 n-1 (alpha radiation). The Russians named Unq-260 kurcha-tovium (Ku-260) for the head of their center, Ivan Kurchatov. (See details in the next section, History. )... 

The first actinide metals to be prepared were those of the three members of the actinide series present in nature in macro amounts, namely, thorium (Th), protactinium (Pa), and uranium (U). Until the discovery of neptunium (Np) and plutonium (Pu) and the subsequent manufacture of milligram amounts of these metals during the hectic World War II years (i.e., the early 1940s), no other actinide element was known. The demand for Pu metal for military purposes resulted in rapid development of preparative methods and considerable study of the chemical and physical properties of the other actinide metals in order to obtain basic knowledge of these unusual metallic elements. 

Chemical and Physical Properties of Plutonium in Aqueous Solution... 

Venkatesan, K.A., Robertselvan, B., Antony, M.P., Srinivasan, T.G., Vasudeva Rao, P.R. 2006. Physical and plutonium retention properties of hydrolytic and radiolytically degraded tri-n-amyl phosphate. Solvent Extr. Ion Exch. 24 747-763. 

Uranium-plutonium mixed oxides Uranium-plutonium mixed oxides (MOX) are becoming increasingly important, since plutonium is produced during the reprocessing of spent fuel elements. In these mixed oxide fuel elements a mixture of uranium(IV) and plutonium(IV) oxides with a plutonium content of 3 to 4% is utilized instead of ca. 4% 235u-enriched uranium(IV) oxide. Such fuel elements have similar nuclear physical properties to the standard elements with and can therefore be used in their place. 

Plutonium has physical properties which cannot be accounted for within the local density-functional approximations. It undergoes a very large lattice expansion (a -> 5) at 600 K, but the L(S)DA cannot predict this. The reason is that this scheme cannot describe correlations sufficiently accurately. The / states are itinerant in the light actinides but localized in the... 

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