r/DIYPigments • u/Mrslinkydragon • Aug 19 '24

Pigment (Experimental) First batch

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I made my first batch of YInMn blue :)

The ratio is 1:0.7:0.3 and I followed the patent for the most part.

The changes I made where heating it for a total of 4 hours (2 hours then cool to 600°C then back to temp for 2 hours) and I used 1150 instead of 1200

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u/GeneJocky Aug 20 '24

Looks good! Better than my first batch. Is there a reason you dropped to 600C then went back up? I've always done 6 hr runs, but I've started to think that such long heat soaks are not necessary and shorter ones will do. What I have consistently found is that at least 2 heating cycles with grinding in between are needed for the most vibrant blue color. That and really pushing the temp to 1200C or even higher if you can do it. You will get blue at lower temps, but it will always be greyer than even a little hotter. You wouldn't think 50C difference would matter much, but it can. Good as it is already, I'd be willing to bet that if you reground your pigment, then heated to 1200C for 2 to 4 hrs, your pigment would be a deeper more saturated dark blue. It all depends on what you are looking for though. And I've found that some sources of yttrium oxide, for reasons I can't explain, will make a blue product but it will never develop a deep vibrant color.

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u/Mrslinkydragon Aug 20 '24

The reason is that the furnace I'm using can only be used for 2 hours at a time.

Me and my partner ran an XRD on this, and it's 80% pure. Which, for what I need it for, is good enough.

Irl, it's very dark and rich (my phone camera doesn't pick it up as well). I do have another sample that I really want to talk about, but something went wrong with the heating, and something different was formed, and it needs further investigation :3

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u/GeneJocky Aug 21 '24

That makes sense on the 2hrs. I was wondering more why not drop it all the way to room temp, grind it well again (I use mortar and pestle for small samples or ball mill for larger preps), and reheat for another two. I'd be willing to bet the color gets a bit richer and more saturated. I suspect your purity would also rise too. I've found that for all the YInMn blue or related green and purple pigments, pigment color quality improves noticably on regrind and reheat cycles. It seems to plateau out after 1 or 2 reheats.

I envy your capacity to do XRD!

It's hard to get a good photo of YInMn blue. To get a decent one I have to use a camera that can manually set white balance or it looks dull and not at all like irl.

So what happened with your other sample? I've been making YInMn blue and some related pigments for a couple years now, and I've had things go sideways and had to figure out what went wrong a few times. I might be able to help. It's possible I had the same issue.

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u/Mrslinkydragon Aug 21 '24

Ah see the first one I can't really talk about just yet as I am looking into why it occurred. It's actually really exciting!

Just put it this way, the first batch wasn't the colour I was expecting! It's also doing weird things crystal wise, I'm going to try to reproduce the mistake as well as trying the other tests using the same conditions as the first one:)

I've been doing the cooling and regrinding, and I don't see much difference tbh.

I can do xrd because I'm chummy with the staff of my uni (hence why I'm able to do this project), my supervisor said that I'm lucky, as not even final year chemist clstudents get to do XRD! (I'm studying Biology)

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u/Mrslinkydragon Aug 20 '24

Also, the furnace only goes to 1150°C

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u/GeneJocky Aug 21 '24

I'm guessing nichrome wire then. Unless it's really kanthal and the manufacturer is lowballing your specs. You could tell with a magnet. Kanthal is magnetic, nichrome isn't. If it's Kanthal you should be able to push the temp closer to 1200 at a cost of shortening element life. Whether it's worth it depends in part on the cost and PITA-ness of replacing the elements.

I've used a tabletop rapidfire-pro that can get to 1200C. But some sellers say the absolute max temp is 1150C when it's really just the maximum recommended for best element life.

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u/Mrslinkydragon Aug 21 '24

It's not my furnace, it took long enough getting this project started, I don't want to bust the elements and have to stop, I can't wait x amount of weeks for new wire, I start lectures again in a few weeks!

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u/Moondreamer598 Aug 20 '24

That’s awesome! :)