Source: {"pile_set_name": "USPTO Backgrounds"}

It has recently been found, as disclosed in pending U.S. patent application No. 855,517, now U.S. Pat. No. 4,822,590 that singular molecular layers of layer-type transition metal dichalcogenides, such as MoS.sub.2, TaS.sub.2 and WS.sub.2, can be prepared by intercalating such compounds with lithium and then reacting the intercalated compound with water. This gives rise to a suspension of single molecular layers of the transition metal dichalcogenides in water.
Attempts have been made in the past to produce sheet-like forms of metal dichalcogenides as revealed, for example, in U.S. Pat. No. 4,299,892 to Dines and Chianelli. Here, an amorphous transition metal dichalcogenide product is prepared by low temperature non-aqueous precipitation of the compound from mixtures of the metal salts. The amorphous products are converted into sheets of metal dichalcogenides referred to in the patent as having a "rag-like" structure by controlled heating at temperatures between 250.degree. and 400.degree. C. However, neither the end product, nor the intermediate product, are oriented films or sheets, that is films or sheets wherein the crystalline c-axes of single layers of the metal dichalcogenide are aligned.
U.S. Pat. No. 4,647,386 to Jamieson discloses an intercalated transition metal based solid lubricating composition. A transition metal dichalcogenide is intercalated with a metal, preferably a coinage metal.