Jump to content

Rare Earth Oxides


Recommended Posts

I did a forum search on rare earth oxides (lanthanides), and came up with little to nothing. The forum has been slow, so perhaps a good time to ask if anyone is using, or experimenting with rare earths? I have most of them, tested them on very small levels. The only picture I have is a test I did some years back: 5% neoydium oxide. Thoughts, experience, input?

 

>> one sec, need to go download my picture... sorry. (Having problems with uploading) error code 503

 

Nerd

Link to comment
Share on other sites

love the color!  but, nerd, i noticed that it crazed.  i like the fact that you use my camera.  reading about all the fancy ones necessary for good pictures made me think mine is inadequate.  i see that it is not.

 

not changing the subject, the video i watched yesterday about flocculating and deflocculating made me wonder why we bother with all this when it seems that if we could just get the glaze or slip to be at a perfect neutral, neither acid or base, our troubles would be over.  (dropped chemistry in high school so i don't know what i am talking about technically.)

Link to comment
Share on other sites

Yes that purple glaze looks to be extremely crazed.

Not a functional surface for sure.

Rare earth minerals for me on my scale of output would mean an uptick in prices that would not merit the cost. 

I'm sticking to minerals that they have not moved in decades like kingman feldspar and albany slip.They now are beyond rare but I got them cheap long ago.

Link to comment
Share on other sites

Great color! I could see some pendants in that glaze. That color is very popular in women's clothing in some places.

The crazing is distracting but I think that is a function of a crystalline glaze and the need to overtire it to get the crystal development.

Marcia

Link to comment
Share on other sites

What kinds of places stock the lanthanides?

 

As a fellow UK resident, you might try asking http://www.ctmpotterssupplies.co.uk

 

I managed to get some cerium from them after it ceased to be in their catalogue. IIRC they

are associated with a company that sells more exotic stuff.

 

.... From their colouring oxides page

We are happy to supply companies with raw materials for other uses and, in fact, our parent

company specializes in metal compounds and rare earths such as cerium oxide, cobalt oxide,

cobalt carbonate, copper oxide, cuprous and cupric, copper carbonate, erbium oxide, iron chromite,

lithium carbonate powder and crystalline, manganese carbonate, manganese dioxide, neodymium

oxide, nickel oxide, praseodymium oxide, tin oxide, vanadium pentoxide etc and so we can usually

offer a good price for small and medium lots of these and many other materials; for larger lots we

will liaise with our parent company for you.

 

Edit: put quote in italics.

Link to comment
Share on other sites

 

The only picture I have is a test I did some years back

 

Yes, I know how badly it crazed: was still dialing in at the time.You guys are merciless!!! ROFL

 

Joel: I was fortunate/blessed when I made my first large purchase from the supplier in St. Louis. An older man owned it just a year prior to Ryan buying him out. I made my initial order of kilns, slab roller, extruder, frits, colorants..etc etc etc to begin my journey into the twilight zone. He called me when he was ready to deliver everything and asked if I wanted some rare earth materials. The previous owner apparently had been stocking several for a client who folded up. I got nearly 10 lbs of praz, yttrium, samarium, europium, neoydium, (vandium), and one other that I cannot remember for $10lb. (mixed amounts of each.) It had been sitting for some time and he wanted it out. So I caught a very timely break.

 

Nerd

Link to comment
Share on other sites

For the sake of completeness, and old ref but quite a good one.

http://www.ceramicstoday.com/articles/lanthanides.htm

 

I used to have a friend in the 1980s who did macro-crystaline glazes, including one

using Neodymium. This does, of course have a startling colour change between

fluorescent and incandescent lighting.

https://en.wikipedia.org/wiki/Neodymium

especially

https://en.wikipedia.org/wiki/File:Neodymium_glass_light_bulb_under_fluorescent_and_incandescent_light.jpg

Link to comment
Share on other sites

Peter:

Thanks for the links, have read the Wiki info, but the first one was new to me. In going through it, in my limited testing I would agree. Let me throw a curve ball into this topic.

1. Crystalline is an ionic bond, most all other standard glazes are covalent (shared molecules).

As I understand it (emphasis on understand), crystals are HCP (hexagonal closed packed). Closely arranged order of zinc/silica atoms, but not chemically bonded as with covalent glazes. So standard glaze theories and principles do not apply to the crystals themselves, but the eutectic soup they grow in. So you have an arranged order of ZN and SI, with the big O being the link between the two.

2. So if my thought process is correct (questionable), that would mean that an ionic bond would be subject to electronegative influences. These would occur my manipulating the electronegative values, and the usual thermodynamics.. (big really hot kiln).

Yttrium somehow is influencing the electronegative values because the colorants do not blend as you would normally see when blending multiple colorants. Praz is highly electropositive that affects crystals somehow: do not have my head around it yet. All I know when added in small amounts it changes the crystal formation and size.

So my interest in rare earths is not so much colorant/s, but rather their effect chemically. If only I had not met that girl in 9th grade who led me astray, I would have a chemistry degree. Feel free to disagree, prove-disprove.

Nerd

Link to comment
Share on other sites

I think I need to state that growing crystals is not a problem, I am just venturing into new territory. Marcia, hold temps are the primary component of development: but I am researching alternate methods of manipulating growth and size.

Base Line

 

This tile is from 4 years ago, so growing them is not an issue for me.

 

Peter, from the article posted:

 

The electrons of the atoms, which are negatively charged, exert forces of attraction or repulsion on others which are in close proximity.

This is the area I am studying; the only reference made in the entire article. I firmly believe there are ways to manipulate crystal growth beyond the tried and true methods of glaze formulation and ramp hold cycles. I have known for some time I am also dealing with a REDOX reaction, but I still think there is more to it.

 

Nerd

Link to comment
Share on other sites

Have you looked at "Materials Science and Engineering: An Introduction"? The older (say 6th) edition should be pretty cheap. The content usually doesn't change much with university textbooks. I know there are chapters on crystal structure and bond strengths. Unfortunately I wasn't interested in pottery and glazes when I took my material science classes. 

Link to comment
Share on other sites

Peter:

looked around this morning for a test piece I did two years ago, apparently I tossed it. Was working on a red oxidation using iron, yttrium, and samarium. The center of was turning red, the rest variegated. Will run it more later this year and post results. Was trying to perfect it for the supplier in St. Louis, but got sidetracked working my day job- as usual.

Nerd

Link to comment
Share on other sites

  • 1 month later...

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.