Graphene

It can be said that graphite is composed of single planes, layers of one carbon atom thick, and graphene, arranged one above the other.

An excerpt from the article 19 facts about graphene

The term “graphene” appeared in the 1960s. In 1961-1962, Hans-Peter Boehm published a study of extremely thin graphite flakes and termed them “graphene” for the hypothetical single-layer structure.