${\rm MgB}_{2}$ Thin Films Prepared on Cu Substrates

MgB
₂
thin films were prepared on polycrystalline Cu substrates by using an electron beam evaporation technique. The J
_c
of MgB
₂
thin film on Cu plate reached very high J
_c
of about 1 times 10
⁷
A/cm
²
at 4.2 K and 1 T. We think that this result may show the possibility of realization of a coated type tape-shaped MgB
₂
superconducting wire.