[time-nuts] Better quartz crystals with single isotope ?

[jimlux]

On 4/22/18 9:19 AM, Poul-Henning Kamp wrote:
> Silicon comes in a number of isotopes but 95% of it is Silicon-28.
> 
> When you make pure mono-crystaline silicon, you get 50-60% better
> thermal conductivity if you only use Silicon-28 atoms.
> 
> Yes, you read that right:  50-60% improvement for removing the
> remaining 5% other silicon isotopes, and for this and other reasons,
> sorting silicon atoms by isotope is now a thing, which amongst other
> side effects have made the Advogardo Project possible.
> 
> I can't help wonder if there may be similar interesting effects in
> quartz crystals, if they were monoisotopic ?
> 
> Several relevant mechanisms can be imagined, lower internal damping,
> higher stiffness etc. etc.
> 
> We know a LOT about quartz and have a very good theory for its
> behaviours, but i find no signs anybody has ever touched monoisotopic
> Quartz.
> 
> The obvious experiment is not rocket-science, nor does it demand
> inordinate resources for amateurs, see for instance from 03:35:
> 
> 	https://archive.org/details/59554KrystallosCF
> 


A note the cigarette in the guy's hand - trace contaminants probably 
increase the yield <grin>

I've looked into "garage manufacture" of crystals, although I was 
looking more at Cr and Ti doped alumina. The movie looks like it's using 
the "solution" approach (which has also been used to grow synthetic 
emeralds) which is similar to how it happens in nature.  These days, I 
wonder whether  continuous pulling from a melt like silicon boules might 
not be a better strategy.