Ion-Microprobe Analysis of Rare Earth Elements in Oceanic Basalt Glass.

AbstractIon microprobe analysis ofperovskite from kimberlites and alnöites permits the accurate determination of La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Er and Yb at the part per million level. Other rare earth elements (REE) are subject to interferences in the mass spectrum caused by matrix-derived molecular ions and cannot easily be determined with comparable precision. Chondrite-normalized plots of the ion probe REE data are smooth curves, confirming the superiority of this technique over electron microprobe methods at the levels of REE abundance found in these perovskites. The perovskites analysed contain between 2.8 and 7.1 wt. % REE oxides and are highly enriched in the light REE, having La/Yb ratios of 577–3229. These La/Yb ratios are not representative of the parental magmas but result from REE fractionation during crystallization of the perovskite. Parental magma La/Yb ratios are estimated to be of the order of 120–650. The lower La/Yb ratios (80–200) found for whole-rock kimberlites are considered to result from contamination by relatively heavy REE-enriched crustal material.

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Problems in electron microprobe analysis of the lanthanides: The x-ray lines

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100134594 ◽

1990 ◽

Vol 48 (2) ◽

pp. 200-201

Author(s):

P. F. Hlava

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Atomic Number ◽

Electron Microprobe ◽

Microprobe Analysis ◽

Electron Microprobe Analysis ◽

Chemical Behavior ◽

X Ray ◽

Lanthanide Series ◽

Valence Electrons

Electron microprobe analysis of materials that contain the lanthanide series of rare earth elements (REE) in natural abundance ratios presents a difficult and truly unique set of problems due to the their chemical and crystallographic similarity and the complexity of the L-spectra used for analysis. REEs differ from one another by the number of protons in their nuclei and the number of electrons in their second inner shell. There are two series of REEs - the lanthanides, from atomic number 58 through 71 and the actinides from 90 through 103. By convention, when most workers speak of the REEs they refer to the lanthanides plus lanthanum, often yttrium and rarely scandium (because these elements are geochemically associated with the lanthanides proper). The terms REE and lanthanide, when used in this paper, will refer to elements of atomic number 57 through 71. In all of these elements the two outer shells, where the valence electrons reside, are essentially identical resulting in chemical behavior that is also essentially identical.

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Distribution of rare earth elements in coal combustion fly ash, determined by SHRIMP-RG ion microprobe

International Journal of Coal Geology ◽

10.1016/j.coal.2017.10.002 ◽

2017 ◽

Vol 184 ◽

pp. 1-10 ◽

Cited By ~ 85

Author(s):

Allan Kolker ◽

Clint Scott ◽

James C. Hower ◽

Jorge A. Vazquez ◽

Christina L. Lopano ◽

...

Keyword(s):

Rare Earth ◽

Fly Ash ◽

Rare Earth Elements ◽

Coal Combustion ◽

Ion Microprobe

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A Combined Dilution and Line-Overlap Coefficient Solution for the Determination of Rare Earths in Monazite Concentrates

Advances in X-ray Analysis ◽

10.1154/s0376030800009654 ◽

1981 ◽

Vol 25 ◽

pp. 133-137

Author(s):

T. K. Smith

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Atomic Number ◽

Rare Earths ◽

Microprobe Analysis ◽

Matrix Effects ◽

Emission Spectra ◽

X Ray ◽

Overlap Coefficient

The rare earth elements (REE) together give guite complex X-ray emission spectra with a considerable number of overlaps at analytical energies by lines of other REE with lower atomic numbers. Where the concentration of REE is high, as in lanthanide minerals, this Interference is more difficult to rectify. Smith and Gold resolved a similar problem with lower atomic number elements in energy dispersive microprobe analysis by establishing a series of overlap coefficients. They asserted that accurate corrections were necessary because of the relatively poor overall resolution of the instrument and that these should not be limited to the major coincidences. Some of the smaller values had probably been ignored because they were considered statistically Insignificant. The mathematical matrix of Smith and Gold covered 22 elements from fluorine to barium, with intensity coefficients (other than intraelement) quoted from 0.01% to 282.1% and with ZAF corrections necessary in cases of K to L conversion. The overlap coefficients were also adjusted for matrix effects.

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