I was thinking about getting plate that can be safely heated by microwave. What material should I look for? My point is to (partialy) turn microwave into induction heater. Plate like this is already sold by Samsung as "crusty plate", but those are hard to come by - I have seen them only along with new microwave.
In my experience, vitreous ceramic (Luminarc) heats up a lot in a microwave, usually ending up hotter than the food. But I cannot tell you if it has some advantage over heating the food in any other material.
Also, if you really want to eat crispy roasted food, the microwave is probably the least suited heating method for that. I have never used the suggested "crusty plate" but I wouldn't expect much of it.
Ceramic. Microwaves excite certain types of molecules and water being a prime target it heats foods rather quickly.
Ceramic that is glazed (the hardened colorful exterior of the ceramic ware) traps the water inside the clay when the bowls, mugs, plates are made. It makes a skin if you will. The microwave will heat these types of dishes up real fast and hold their heat well because they have a lot of mass compared to other types. I use Pfaltzgraff plates and they are heavy. They are heavy ceramic and if I cook a bowl of cold soup for 3 minutes in it.... I can not touch the bowl. It is screaming hot.
I have some raw ceramic pans (for meatloaf) with no glazing on them. They barely get hot. In a microwave.
Also there is sand mixxed in clay. This is more of a physics question. Good luck.