B in pyrex glass

[jeolunlv12]

Hi, all:

Did anyone test B content in Pyrex glass with EPMA?

Based on Pyrex data, the glass should have around 13% B2O3.

The B is peaked from a B standard, LED2 peak at 191.98 with around 2000 cps. However, at this B peak position, there is barely any counts for B in a pyrex glass (C coated). At 15 KV, 10 nA, and 10 seconds, the B counts are 68 on pyrex glass and peak scan from 180 to 210 can not find any peak.

The EPMA data for this pyrex glass is SiO2 79.5%, Al2O3 2.4%, and Na2O 3.9-4.2%, with total near 87% (both F and Cl are included in analysis, and B is not include in analysis). This is almost same as the reported pyrex code 7740 glass without B2O3.

Any suggestion? Is the B x-ray absorbed by anything in the pyrex glass?

Minghua Ren
UNLV geoscience

[Probeman]

Any suggestion? Is the B x-ray absorbed by anything in the pyrex glass?

Hi Minghua,
Yes indeed there is very, very strong absorber for B ka in Pyrex!

Use CalcZAF and you will see what element it is!

See also this topic:

http://smf.probesoftware.com/index.php?topic=248.msg1186#msg1186

john