a shape other than elliptical similarly other single crystal or polycrystalline substrates may be used for example any of those materials suitable for depositing superconducting thin films also other methods may be used to deposit the thick film onto the substrate and forms of thick film other than the strips described herein may be utilized in an exemplary method according to the invention bi 2 o 3 srco 3 caco 3 and cuo powders are mixed in molar proportions bi sr ca cu of 2 2 2 3 the mixture is ball milled and calcined at least twice to form a powder of nominal composition bi 2 sr 2 ca 2 cu 3 o x wherein x is about 8 9 a thick film of this powder is formed by screening the powder to remove agglomerates mixing the powder with a suitable carrier or binder and screen printing the mixture e g in a strip on a single crystal mgo substrate the film is then dried e g at 300 u00b0 c in air the substrates are heated preferably in air or an oxidizing atmosphere although the atmosphere is not critical to a temperature below the liquidus temperature and are exposed to the beam of an argon laser the beam is focused with a cylindrical lens to give.