Standards for Microanalysis - Rare earth "five" phosphate crystals

SPI Standards for Microanalysis 15 Rare Earth "Five Phosphates" - New and Improved!
Rare earth standards in specially prepared rare earth "five" phosphate crystals

Chinese

Since its introduction a few years ago, the SPI "Five Phosphate" Rare Earth standard has proved to be very popular with geochemists and microanalysts. We used crystals kindly provided and certified by the Chinese Microanalysis Society, but this source has now been exhausted. Consequently we drew on our own resources to make crystals in house. The result is spectacular. We have succeeded in growing crystals which are larger and even more stable than those that we used earlier. In addition, we have quantities now which allow us to offer these compounds on a "loose" basis. In other words, we no longer require the customer to purchase all 15 members of this set together in a single polished mount. You can now buy them individually for the same price as most other items in our DYOS (Design Your Own Standard) series.
The Rare Earth (RE) "five phosphates" are of the stoichiometric form REP₅O₁₄ giving altogether 14 different rare earth elements, plus yttrium. These are suitable for use with both WDS and EDS systems, and now also on laser ablation instruments.

Consider these features:

Relative to the alternatives, these rare earth standards all come in the same highly stoichiometric form REP₅O₁₄, in which the rare earth element is in the most useful concentration range for use as a standard. The polished surfaces are stable and will resist degradation provided they are kept in a dry environment, as one would keep any other delicate standard.

The 15 crystalline compounds making up this standard have been synthesised in a laboratory at the University of Toronto. Evidence of their purity and composition is provided on purchase.

The actual size of each rare earth (REP₅O₁₄) crystal is on the order of 1 mm as illustrated in the pictures accompanying Rare Earth Phosphate Web Page. In any case the homogeneity is outstanding and the CRM's have been synthesized specifically for microanalysis applications.

If purchased as a complete set, these standards are prepared in the highly popular format of all other SPI Standards for Microanalysis, that is, with a built in Faraday cup and electron beam lettering adjacent to each item for easy identification and use in the microscope or microprobe. Lettering is available either as "normal" or as "mirror image" labelling.

It is our opinion that this form of standard is far better than pure metals, oxide powders , some glasses of rare earth elements (REE) or certain of the REEs as halides. Several pure REE metals are out of the question because of their rather rapid oxidation with the moisture found in normal laboratory air and this is a problem even when storage is done in a desiccator. The REE oxides are usually found as a small particle size powder. The REE oxide melts are also not stable enough even for a short time. And some REE-bearing glasses with low concentration of the REE are just not satisfactory for the analysis of real life samples. So that is why the REP₅O₁₄ group of fifteen samples has been used in many EPMA laboratories. And that is why we believe this group of standards is technically the best choice for our customers. We are also told by those who have used this newest of SPI Standards for Microanalysis that it helps the analyst do the analysis more quickly and comprehensively. So while the rare earth phosphate standard mount is more expensive than our original rare earth standard, we believe that the higher cost can be more than justified because of the higher value represented by these REP₅O₁₄ standard crystalline compounds.

Of course a comprehensive manual listing individual compositions is supplied with purchase. Not only that but we show you a photograph of each item in your mount along with an X-ray spectrum of the material. To see the documentation which goes out with each mount take a look at one of our new Spiffy Manuals ® which is created individually for each 15 Rare Earth "Five Phosphates" standard we produce. We keep an Acrobat PDF of each manual in our archives and will supply this to you for a nominal charge, should you ever need a replacement copy.

	Rare earth compound		Composition
The fifteen standard REP₅O₁₄ crystalline compounds and their stoichiometric compositions are as follows:
	Element	REP₅O₁₄	RE₂O₃	P₂O₅	RE	P	O
1.	Lanthanum	LaP₅O₁₄	31.46	68.54	26.83	29.91	43.26
2.	Cerium	CeP₅O₁₄	31.62	68.38	27.00	29.84	43.16
3.	Praseodymium	PrP₅O₁₄	31.73	68.27	27.11	29.80	43.09
4.	Neodymium	NdP₅O₁₄	32.16	67.84	27.57	29.61	42.82
5.	Samarium	SmP₅O₁₄	32.95	67.05	28.41	29.26	42.32
6.	Europium	EuP₅O₁₄	33.15	66.85	28.63	29.18	42.20
7.	Gadolinium	GdP₅O₁₄	33.81	66.19	29.33	28.89	41.78
8.	Terbium	TbP₅O₁₄	34.01	65.99	29.55	28.80	41.65
9.	Dysprosium	DyP₅O₁₄	34.45	65.55	30.02	28.61	41.38
10.	Holmium	HoP₅O₁₄	34.74	65.26	30.33	28.48	41.19
11.	Erbium	ErP₅O₁₄	35.02	64.98	30.63	28.36	41.02
12.	Thulium	TmP₅O₁₄	35.22	64.78	30.84	28.27	40.89
13.	Ytterbium	YbP₅O₁₄	35.70	64.30	31.35	28.06	40.59
14.	Lutetium	LuP₅O₁₄	35.93	64.07	31.59	27.96	40.44
15.	Yttrium	YP₅O₁₄	24.14	75.86	19.01	33.11	47.89

Storage requirements
We recommend that all of the microanalysis standards manufactured by SPI Supplies be kept in a desiccator cabinet when not being used. Some of the elements will, with time, corrode and/or oxidize but to slow down this process, we strongly recommend that a desiccator be purchased at the time of purchase of the microanalysis standard if you do not one already in your laboratory. Your standard does represent an important investment for you and you should take steps to make sure it has the longest possible useful lifetime. Of course, any purchaser of an SPI Supplies standard for microanalysis will always have the option of submitting it at some future date for our Standard Refurbishing Service.

Standards for Microanalysis Main Page
Microanalysis standard maintenance instructions
Microanalysis Standard refurbishing service for SPI Supplies standards

Description		Dimensions		SPI #		PRICE			In Stock
15 Rare Earth Phosphate Standard Mount		25mm diameter x 6mm high		02759-AB		$2800.00			No

To Ask a Question or Make a Comment

To Place an Order or Request a Quote

Return to:

Sunday March 21, 2010 © Copyright 1996 - 2010. By Structure Probe, Inc.
Contacting SPI Supplies and Structure Probe, Inc.
All rights reserved.
All trademarks and trade names are the property of their respective owners.

Worldwide Distributors, Representatives, and Agents Flag logo

SPI Standards for Microanalysis15 Rare Earth "Five Phosphates" - New and Improved!

SPI Standards for Microanalysis
15 Rare Earth "Five Phosphates" - New and Improved!