
YInMn Blue - zeristor
https://en.wikipedia.org/wiki/YInMn_Blue
======
saagarjha
> Under this project, he was particularly interested in synthesizing
> multiferroics based on manganese oxides. He directed Andrew E. Smith
> (Subramanian's graduate student) to synthesize an oxide solid solution
> between YInO 3 (a ferroelectric material) and YMnO 3 (an antiferromagnetic
> material) at 1,093 °C (2,000 °F). The resulting compound was not an
> effective multiferroic; it was instead a vibrant blue material.

The quintessential chemistry story: someone sets out to make something and
ends up creating something useful but completely different by accident.

~~~
dclowd9901
Why does this happen so much? I mean, this is science: shouldn’t chemicals
react as they do in theory? It doesn’t seem like it’d leave a lot to chance.

~~~
quanticle
Computational chemistry involves solving multiple NP-hard problems. There is
an increasing reliance on computational models and simulation, but chemists
realize that the models are approximations (since it's computationally
infeasible to have perfect fidelity simulations). The only surefire way to
observe a compound's properties is to synthesize it and measure.

~~~
OscarCunningham
Surely there can't be any problems in computational chemistry that have
actually been proven to be NP-hard? Simulating an experiment atom-for-atom is
in BQP, which is not known to contain NP (and is suspected not to contain NP).

EDIT: To put it another way, we can't solve NP problems by doing chemistry
experiments.

~~~
0xffff2
Surely you would need to be modelling at a subatomic level to accurately
simulate chemical interactions?

~~~
OscarCunningham
Sure. It's not an essential distinction though, because subatomic physics is
also simulable in BQP.

~~~
selimthegrim
N-representability?

------
CaliforniaKarl
For a small set of other color-related videos, have a look at two from Tom
Scott:

• "The Library of Rare Colors":
[https://www.youtube.com/watch?v=rApTzWboLrA](https://www.youtube.com/watch?v=rApTzWboLrA)

• "I Can't Show You How Pink This Pink Is":
[https://www.youtube.com/watch?v=_NzVmtbPOrM](https://www.youtube.com/watch?v=_NzVmtbPOrM)

The latter video makes me wonder: Is there a good way of finding out if a
monitor, or even an entire color space, can contain this color? This may be a
pigment where you really can't tell exactly what it looks like on-screen,
because either the screen cannot display the color or the color space being
used can not encode the color (or because the camera sensor can't properly
capture the color).

~~~
Darkphibre
I actually ordered some of this Pinker than Pink! As well as Black 2.0 and a
few of his other pigments.

I believe what he's doing is mixing in a pigment that fluoresces from
sunlight, at the same frequency as the primary visible-spectrum pigment. Thus,
more of that frequency of light is coming off the page than the visible light
landing on the page.

It's pretty crazy to look at in sunlight. Indoor, it's not quite as vibrant.

~~~
mturmon
Like the optical brighteners that are used in detergents:
[https://en.m.wikipedia.org/wiki/Optical_brightener](https://en.m.wikipedia.org/wiki/Optical_brightener)

------
myself248
> YInMn Blue is chemically stable, does not fade, and is non-toxic.

I'm calling a big old [citation needed] on a compound that's only existed for
a decade. It might not be acutely toxic, but recently we seem to be finding
all sorts of subtle effects from compounds that've been in common use for
decades.

How does one establish non-toxicity?

~~~
nabla9
You test it with animals.

It's inorganic, has simple structure and contains only non-toxic compounds, so
there is no reason to be worried.

If you want to worry, direct your attention towards Vantablack and other
carbon nanotubes. It has specific target organ toxicity from single exposure
and while it does not appear to be carcinogenic it needs more testing.

~~~
weinzierl
> It's inorganic, has simple structure and contains only non-toxic compounds,
> so there is no reason to be worried.

So is asbestos...

~~~
nabla9
I knew that someone would reply with asbestos when I wrote that. "simple
structure" is there to exclude asbestos.

Asbestos is dangerous because it's a tiny spike that sticks into cell. Just
like nanotube of similar length.

------
wollstonecraft
Why do people get to patent the products of federal grants?

~~~
jcranmer
Why should you deprive an inventor of the rights to his invention merely
because he's funded by the government? Do note that, in these situations, you
have to notify the government of your intent to file a patent (and you lose
the patent if you fail to do so!), and the government gets an automatic
license to the patent.

~~~
JoshTriplett
> Why should you deprive an inventor of the rights to his invention

"Rights" to inventions aren't innate, they're explicitly granted. Why should
we _grant_ an exclusive monopoly on publicly funded research?

~~~
mbreese
To add a profit motive, which in effect accelerates the fruits of the research
being made available to the public and not hidden on the shelf of a lab. At
least, that's the theory...

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del_operator
Reminds me of the story of how Lithium was initially thought help “brain gout”
by dissolving uric crystals, but it still ended up working.

Read an interesting story of a physicist that got curious about it.
[https://www.quantamagazine.org/a-new-spin-on-the-quantum-
bra...](https://www.quantamagazine.org/a-new-spin-on-the-quantum-
brain-20161102/)

------
pacificmint
NPR had a good article about the discovery: "A Chemist Accidentally Creates A
New Blue. Then What?" [1]

[1] [https://www.npr.org/2016/07/16/485696248/a-chemist-
accidenta...](https://www.npr.org/2016/07/16/485696248/a-chemist-accidentally-
creates-a-new-blue-then-what)

~~~
viewtransform
This blue pigment is used on the shrouds of AMD Radeon Pro graphics cards.
[https://www.amd.com/en/graphics/workstations](https://www.amd.com/en/graphics/workstations)

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broahmed
Here's a great article about the discovery of this color, and the pigment
industry in general, which hit the front page of HN a year ago:

The Quest for the Next Billion-Dollar Color

[https://www.bloomberg.com/features/2018-quest-for-billion-
do...](https://www.bloomberg.com/features/2018-quest-for-billion-dollar-red/)

[https://news.ycombinator.com/item?id=16870440](https://news.ycombinator.com/item?id=16870440)

------
zeristor
YInMn is supposed to have high NIR reflectivity useful on a sunny roof. The
Apollo 11 Lunar Module used gold foil to reflect heat, I suppose future
vehicles could have a brilliant blue foil, apt for Blur Origin.

I liked how the lunar module used gold foil, and Apollo the Greek god was the
Sun deity; gold often used to represent the Sun.

~~~
the8472
If all you need is IR reflection for a building then TiO2 based paint will do
the job and is much cheaper. The advantage of YInMn is that it also provides
color.

~~~
zeristor
Under properties one an see the reflectivity and whilst far better than Cobalt
blue, its a long way from Gold and silver:

[https://colourlex.com/project/yinmn-
blue/](https://colourlex.com/project/yinmn-blue/)

------
neonate
Here's a nice interview with the discoverer: [https://news.artnet.com/art-
world/chemist-mas-subramanian-on...](https://news.artnet.com/art-
world/chemist-mas-subramanian-on-the-incredible-discovery-of-yinmn-
blue-973700)

------
zeristor
Yttrium and Indium are two rare earths, Indium especially, used in displays.
Mention has been made that the Indium required makes this pigment expensive.

------
joshu
Apparently it costs $1k/kg right now, if it were even available.

~~~
zeristor
Indium looks to cost $5 a gram, twice the price of silver, although it’s
supposed to be as ubundant

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creeble
Is it still true that there are no real inorganic red dyes? Or is that ancient
history?

~~~
gimmeThaBeet
It may depend on the definition of red, but that doesn't sound true at all.
Cadmium red, lead tetroxide, cinnabar, all in use for a hundred+ to even
thousands of years.

I think where that comes from is that there isn't really an inorganic red that
is all of stable, durable, non-toxic, and only then even then good looking.

If I remember correctly, once Mas Subramanian sort of stumbled into "I guess I
can try to make pigments with these compounds" he's tried making other colors,
but sort of the big prize is in finding a good red with properties similar to
YInMn.

~~~
creeble
>>stable, durable, non-toxic, and only then even then good looking.

Yes, I think that was the combination.

I was thinking in particular red car paint -- it was only organic compounds
through the early 2000's, and therefore all of it fades.

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zeristor
The article makes no mention of how the pigment makes the blue colour.

~~~
beautifulfreak
It's due to the "trigonal bipyramidal" lattice structure. By changing atoms in
the structure, they've created pigments with a range of colors.
[https://ws680.nist.gov/publication/get_pdf.cfm?pub_id=921441](https://ws680.nist.gov/publication/get_pdf.cfm?pub_id=921441)

~~~
zeristor
Excellent find!

This article also talks of the three other variants for different colours

------
zeristor
As mentioned in this YouTube video by Seeker, albeit in passing, but credit
where it’s due:

[https://youtube.com/watch?v=lolgjjr8QIU](https://youtube.com/watch?v=lolgjjr8QIU)

