Properties of MgB₂films grown at various temperatures by hybrid physical–chemical vapour deposition

A hybrid physical-chemical vapour deposition (HPCVD) system consisting of separately controlled Mg-source heater and substrate heater is used to grow MgB2 thin films and thick films at various temperatures. We are able to grow superconducting MgB2 thin films at temperatures as low as 350 degrees C with a T-c0 of 35.5 K. MgB2 films up to 4 mu m in thickness grown at 550 degrees C have J(c) over 10(6) A cm(-2) at 5 K and zero applied field. The low deposition temperature of MgB2 films is desirable for all-MgB2 tunnel junctions and MgB2 thick films are important for applications in coated conductors.