Neodymium oxide chloride

Neodymium oxide was first isolated from a mixture of oxides called didymia. The elemeut ueodymium is the secoud most abuudaut lanthanide elemeut in the igneous rocks of Earth s crust. Hydrated neodymium(III) salts are reddish and anhydrous neodymium compounds are blue. The compounds neodymium(III) chloride, bromide, iodide, nitrate, perchlorate, and acetate are very soluble neodymium sulfate is somewhat soluble the fluoride, hydroxide, oxide, carbonate, oxalate, and phosphate compoimds are insoluble. 

Neodymium Nickel Phosphorus Aluminum, aluminum(III) chloride, ethylene, 1,4-dioxan, hydrogen, methanol, nonmetals, oxidants, sulfur compounds... 

In 1885 C. A. von Welsbach isolated two elements as oxides, praseodymium (the word meaning green twin ) and neodymium (meaning new twin ), from a mixture of lanthanide oxides called didymia. The oxides can be transformed to fluorides by reaction with HF at 700°C (1,292°F), or with NH4HF2 at 300°C (572°F). The hydrated fluorides are then dehydrated in vacuo in a current of HF gas. The metals praseodymium and neodymium are obtained via metallothermic reduction with calcium at approximately 1,450°C (2,642°F), or via electrolytic reduction of the melts. The metals can also be obtained from anhydrous chlorides, obtained via reaction of the oxides with ammonium chloride at 350°C (662 °F), which are then reduced with lithium-magnesium at approximately 100°C (212°F). 

Na2S2 DISODIUM DISULFIDE 1146 NdOCI NEODYMIUM CHLORIDE OXIDE 1190... 

The preparation of amalgams of lanthanum, neodymium, and cerium by electrolysis of the anhydrous chlorides in alcoholic solution has already been described. The electrolysis of a rare earth chloride in water solution proves unsatisfactory because of the production of a precipitate of hydrous oxide at the cathode and the liberation of chlorine at the anode. 

The Nd YAG ceramics were prepared from precursor powder synthesized by using chemical coprecipitation method, with mixed aqueous solutions of aluminum, yttrium, and neodymium chlorides as sources of the cations and solution of ammonium hydrogen carbonate as precipitant. The precursor was calcinated at 1200 °C to obtain oxide raw powders. The powders were compacted and finally sintered at 1750 °C in vacuum for 5-20 h [90]. 

Watson (1980), Watson et al. (1981) and TiUey and Andersen (1981b) prepared bis(pentamethylcyclopentadienyl) ytterbium, lutetium, neodymium and samarium chlorides and iodides. Some physical data of these compounds together with those of the other complexes with substituted cyclopentadienyl ligands are given in table 8. The following synthetic methods have been used ytterbium metal is oxidized by CjMejI in the presence of Lil in ether to give, via CjMejYbl, the complexes shown in eq. (20). In the absence of Lil, only dimeric pentamethylcyclopentadiene was isolated. 

The most common raw materials for the REM molten salt electrolysis are in the RE " state, such as RE2O3, RECI3. But RE " still exists to a certain extent in the molten salts, especially in the chloride melts, some rare earth metal elements have presented a higher level of divalent oxidation states, such as neodymium, samarium, europium, dysprosium, thulium, and ytterbium, which result in a lower current efficiency. For Sm and Eu molten salt electrolysis processes, even no metals can be obtained at the cathodes due to a cyclic transformation of Sm VSm (Eu /Eu ) and Sm /Sm (Eu /Eu ) on the electrodes during electrolysis. And some of the rare earth metal elements show tetravalent oxidation states at the chlorine pressure far in excess of atmospheric pressure, such as Ce. Most of the rare earth metal elements in oxidation state of -1-4 are not stable in chloride melts, because the reaction occurs according to the following equation RE " -I- Cl = RE -" -I- I/2CI2. 

Cathro, K.J., Deutscher, R.L. and Sharma, R.A. (1997) Electrowiiming magnesium from its oxide in a melt containing neodymium chloride, J. Appl. Electrochem., 27, 404-413. 

In the assessment of the refining performance of uranium, systematic data has been reported for the chemical properties of uranium complex in various alkali chlorides such as LiCl-RbCl and LiCl-CsCl mixtures [3-5], Information on the coordination circumstance of solute ions is also important since it should be correlated with stability. The polarizing power of electrolyte cations controls the local structure around neodymium trivalent Nd " " as an example of f-elements and the degree of its distortion from octahedral symmetry is correlated with thermodynamic properties of NdClg " complex in molten alkali chlorides [6]. On the other hand, when F coexists with Cr in melts, it is well-known that the coordination circumstances of solute ions are drastically changed because of the formation of fluoro-complexes [7-9]. A small amount of F stabilizes the higher oxidation states of titanium and induces a negative shift in the standard potentials of the Ti(IV)ITi(ni) and Ti(III)ITi(II) couples [7, 8], The shift in redox potentials sometimes causes specific electrochemical behavior, for example, the addition of F to the LiCl-KCl eutectic leads to the disproportionation of americium Am into Am " and Am metal [9],... 

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