As ceramic layers for cookware several oxidic materials are possible. Manufacturers companies do not publish this information, but is known, for example, ceramic layer of TiO2. Mixtures of TiO2 + Al2O3 or pure Al2O3 are also known. I do not know whether other ceramic materials are used as a standard, but there is nothing to prevent it. Many natural and synthetic silicates can also be used successfully. Important is the granulometry of the powder: powder must be free-flowing because it is applied by means of plasma spraying.
Ceramic layers themselves are not non-stick. In order to be non-stick, the ceramic layers have to be impregnated with teflon. This is just the structure of all ceramic layers for cookware: hard and porouse ceramic underlayer + sealing with thin teflon layer, penetrating into pores and cracks of ceramic. If even the uppermost layer of teflon should be damaged, in pores of the ceramic layer teflon remains undamaged. Due to this double-layer construction, the "ceramic cookware" reach longer service life than "teflon cookware".