Magnetic property characterization system employing a single sensing coil arrangement to measure AC susceptibility and DC moment of a sample

A method of measuring ac and dc magnetic characteristics of a sample, said method including:

• (a) magnetically coupling said sample to a sensing coil arrangement including a pair of sensing coils connected in opposition;
• (b) for measuring dc moment of said sample, applying a dc magnetic field to said sample, moving said sample relative to said sensing coil arrangement, and receiving and measuring signals from said sensing coil arrangement;
• (c) for measuring ac susceptibility of said sample, applying an alternating magnetic field to said sample, and receiving and measuring signals from said sensing coil arrangement;
• and
• (d) generating values associated with ac susceptibility and dc moment of said sample in response to signals received and measured during said steps (c) and (b), respectively.

A magnetic measuring system for measuring ac and dc magnetic characteristics of a sample, said system including:

• dc magnetic field applying means for applying a dc magnetic field to said sample during a dc moment measurement;
• ac magnetic field applying means for applying an alternating magnetic field to said sample during an ac susceptibility measurement;
• a sensing coil arrangement including a pair of sensing coils connected in opposition, said sensing coil arrangement producing an output related to the magnetic characteristics of the sample;
• coupling means connected to said sensing coil arrangement for coupling said sensing coil arrangement to signal sensing means during said dc moment measurement, and during said ac susceptibility measurement,
• moving means for moving said sample relative to said sensing coil arrangement during said dc moment measurement;
• said signal sensing means for sensing the outer of said sensing coil arrangement;
• and
• processing means, connected to said signal sensing means, for generating a first value and a second value, one of said first and second values indicating ac susceptibility of said sample in response to said sensed output, and the other of said first and second values indicating dc magnetic moment of said sample in response to said sensed output.

A magnetic measuring system for measuring ac and dc magnetic characteristics of a sample at cryogenic temperatures, said system comprising:

• a cryogenic chamber;
• at least one sensor coil arrangement disposed within said chamber, said sensor coil arrangement including a pair of sensing coils connected in opposition;
• moving means for moving said sample relative to said sensor coil arrangement during a dc magnetic measurement;
• dc field applying means for applying a dc magnetic field to said sample during said dc magnetic measurement;
• alternating field applying means for applying an alternating magnetic field to said sample during an ac magnetic measurement;
• and
• measuring means, coupled to said sensing coil arrangement for performing said dc measurement by measuring at least one dc magnetic characteristic of said sample and for performing said ac measurement by measuring at least one ac magnetic characteristic of said sample, said ac and dc magnetic measurements both being performed successively using said sensor coil arrangement without requiring said sample to be removed from said chamber.