an apparatus and a method is disclosed for in - situ deposition of thin films of high - temperature superconductor compounds on a substrate that involves exposure of the substrate to a high pressure of oxygen and / or a high vapor pressure of volatile metallic elements such as hg , tl , pb , bi , k , rb , etc ., for stabilization of the crystal structure . such compounds include basically all known hts materials with t c higher than 100 k . the method is based on pulsed laser deposition and a cyclic process , wherein the substrate is shuttled between a “ closed ” and an “ open ” position . in the “ closed ” position it is exposed to high temperature and high pressure of oxygen and / or volatile metallic species . in the “ open ” position , it is kept under low pressure and exposed to pld plume . short deposition bursts occur while the substrate is in the open position . these are followed by longer time intervals of re - crystallization and structural relaxation , which occur while the substrate is in the “ closed ” position .