ISOLIERUNG FUER SUPRALEITER

This invention is a superconductor having a generally substoichiometric oxygen, nickel oxide insulation between superconduction strands. The superconductor is to have an operating temperature below 250 degrees kelvin, and has multiple superconductors, with a cladding of nickel on the strands, and an adherent coating of nickel oxide formed on the outer surface of the cladding. The nickel oxide has stoichiometric or less than stoichiometric oxygen (but not greater than stoichiometric oxygen) to be electrically insulating at the operating temperature of the superconductor. Thus high thermal conductivity strand insulation capable of withstanding strand to strand voltages of greater than 50 volts is provided to substantially eliminate coupling currents between the strands, and nickel oxide having areas of semiconducting due to containing more than stoichiometric oxygen is avoided.