Patent ID: 6226538
Filing Date: 2001-05-01
Classification: G01R,H01L,Y10S

Abstract:
A magnetic sensor comprising:a flux transformer having two coils electromagnetically connected to each other, said coils being formed on a first substrate; anda SQUID having an annular part opposite to said flux transformer, said annular part facing one of said coils of said flux transformer, said annular part being formed on a second substrate, a predetermined portion of said annular part forming a Josephson junction by covering a step edge which traverses thereunder,whereinone of said coils is larger than the other one of said coils;the larger one of said coils is larger than said annular part;the smaller one of said coils faces said annular part;an outside diameter of said annular part is not greater than 5 mm;both of said coils and said annular part are made of a superconducting material comprised of Ho, Ba, Cu and O;said first substrate is comprised of a sapphire substrate and a cerium oxide layer is interposed between said sapphire substrate and said coils; andsaid second substrate is comprised of Sr, Ti and O.