SEM/Optic pictures of a spinel ceramic

During my studies I had to do a 6-months project about a very particular kind of ceramics called spinel.

I'll try to be as short as possible, here you can find the atomic structure of a spinel :

With some zoom-ins on tetrahedral (left) and octahedral (right) sites :

White balls are Oxygen atoms, black ones are magnesium, the grey ones are Aluminium.

Those pictures are courtesy of my lab, and show spinel powder (before "baking" it, or I should say sinter it to be scientifically accurate) :

Also this is the machine we use to transform the powder into a unified and solid ceramic :
We could think this can produce a lot of spinel, but actually we can't make more than a 5 grams sample in twelve hours. Ceramics are that resistant thanks to that very particular manufacturing process, which I may describe in a next post.

Those are optic observation with true colors, obtained thanks to a optical microscope :

The black object is residue of an electric contact, the middle rod was the titanium cable and the "hair" was an insulating glass fiber braid.

This is some silicium residue, thanks to its cristallinity it exhibits nice colors (contrast is low so hard to notice them):

Believe it or not, this is gold, used to be 100% pure gold but the oven treatment + several other processes altered it :

I'm keeping several other pictures for future posts, do not hesitate to ask me questions about the process to obtain the spinel or the method to take such pictures!

Follow me for more scientific content to come :)