Accession Number : AD0613228

Title :   RARE EARTH NICKEL OXIDES,

Corporate Author : MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s) : Wold,Aaron ; Post,Benjamin ; Banks,Ephraim

Report Date : 17 APR 1957

Pagination or Media Count : 3

Abstract : LaNi03, containing nickel in the trivalent state was prepared and its structure studied by X-ray diffraction methods. The dimensions of the rhombohedral pseudo-cell are a = 7.676=0.002 A., alpha = 90 degrees 43 minutes. The dimensions of the primitive rhombohedral cell are alpha sub p = 60 degrees 49 minutes, a = 5.461 A. The hexagonal form of this cell has the following dimensions: a = 5.456 A., c = 13.122 A. Neodymium oxide reacts with nickel (II) oxide, in the presence of sodium carbonate, to form a single phase whose composition may vary between Nd 1.67Ni(+2) 0.72Ni(+3) 0.41 03.84 and Nd 1.75Ni(+2) 0.57 Ni(+3) 0.43 03.84. An increase in the ratio Nd:Ni results in the formation of more trivalent nickel. With the exception of one very weak line at 2 theta = 31. 2 degrees, all the lines of the X-ray diffraction patterns out to 2 theta = 75 degrees could be indexed satisfactorily on the basis of a monoclinic unit cell with a = 3.92 A., b = 6.16 A., c = 3.77 A. and beta = 92.4 degrees. Samarium, gadolinium and yttrium oxides do not appear to form stable compounds with nickel (II) oxide under the conditions used to form the other rare earth nickel oxides. The product of reaction between lanthanum oxide, samarium oxide and nickel (II) oxide, in the mole ratio 1:1.4, was a new phase which seemed to be isomorphous with the phase obtained from the reaction of mixtures having compositions between 2Ni0.1.5Nd203 and 2Ni0.1.75Nd203.

Descriptors :   (*RARE EARTH COMPOUNDS, NICKELATES), (*NICKELATES, CRYSTAL STRUCTURE), X RAY DIFFRACTION, TRANSITION METALS, OXIDES, LANTHANUM COMPOUNDS, NEODYMIUM COMPOUNDS, SAMARIUM COMPOUNDS, GADOLINIUM COMPOUNDS, YTTRIUM COMPOUNDS, PREPARATION, CHEMICAL ANALYSIS, TABLES(DATA), GEOMETRIC FORMS

Distribution Statement : APPROVED FOR PUBLIC RELEASE