Image and sample geometry effects in SQUID magnetometers

This review concerns the interpretation of the signal provided by SQUID magnetometers designed for measurements of magnetization and magnetic susceptibility. ‘‘Image effect’’ refers to the influence of superconducting elements in the vicinity of the sample and detection coil. Several exact and approximate methods are presented for calculation of how the device sensitivity G(r) varies with position r of a unit dipole sample in the presence of a superconducting shielding tube. In particular, the relative decrease of G(r) is approximately given by the third power of the ratio of the detection coil and shield diameters, and the effect of the shield’s finite length is found to be negligible in practical situations. A survey of complex detection coils (Helmholtz, saddle‐type, gradiometer, and second derivative coil) includes calculation of the optimum spacing of the Helmholtz pair in the presence of a superconducting cylinder. The image effects due to the properties of the SQUID circuit and the field‐dependent ...

[1]  G. Romani,et al.  Oscillating sample superconducting magnetometer , 1977 .

[2]  D. Edwards,et al.  Small solenoid with a superconducting shield for nuclear‐magnetic‐resonance near 1 mK , 1982 .

[3]  SQUID-magnetometer with open-ended horizontal room-temperature access , 1984 .

[4]  Simon Foner,et al.  Superconducting magnet image effects observed with a vibrating sample magnetometer , 1983 .

[5]  D. M. Ginsberg,et al.  Optimum Geometry of Saddle Shaped Coils for Generating a Uniform Magnetic Field , 1970 .

[6]  W. S. Goree,et al.  Magnetometers using RF-driven squids and their applications in rock magnetism and paleomagnetism , 1976 .

[7]  J. Philo,et al.  High‐sensitivity magnetic susceptometer employing superconducting technology , 1977 .

[8]  Magnetic field shielding by a superconducting cylindrical tube of finite length , 1976 .

[9]  M. Pelizzone,et al.  A SQUID susceptometer for fields up to 8.5 tesla , 1981 .

[10]  Magnetic shield of high-T/sub c/ Bi-Pb-Sr-Ca-Cu-O superconductors at 77 K for SQUID measurements , 1991 .

[11]  M. Ishizuka,et al.  A SQUID Magnetometer for Simultaneous Measurements of Spontaneous Magnetization and AC Susceptibility around the Magnetic Phase Transition Point , 1980 .

[12]  S. Vitale,et al.  Superconducting susceptometer for high‐accuracy routine operation , 1982 .

[13]  S. R. Hoon,et al.  The direct observation of magnetic images in electromagnet vibrating sample magnetometers , 1988 .

[14]  J. Mallinson.  Magnetometer Coils and Reciprocity , 1966 .

[15]  J. Overweg,et al.  An automatic frequency-sweeping SQUID susceptometer , 1983 .

[16]  SQUID holder with high magnetic shielding , 1990 .

[17]  T. Sumner,et al.  Convectional magnetic shielding , 1987 .

[18]  D. Dummer,et al.  Elimination of the induced current error in magnetometers using superconducting flux transformers , 1987 .

[19]  K. Gramm,et al.  SQUID Magnetometer for Mangetization Measurements , 1976 .

[20]  M. Castellano,et al.  Null input current SQUID magnetometer for the measurement of the transition temperature of high‐Tc superconducting samples , 1988 .

[21]  M. Ballauff,et al.  Magnetic susceptibility and order parameter of nematic liquid crystals as determined by a high‐temperature SQUID magnetometer , 1991 .

[22]  Superconducting magnetometer for high resolution susceptibility measurements , 1976 .

[23]  J. Park,et al.  A calculation of the effect of coaxial superconducting shields on the flux sensitivity of SQUID pick-up coils , 1984 .

[24]  R. A. Webb,et al.  Principles and methods of low-frequency electric and magnetic measurements using an rf-biased point-contact superconducting device , 1972 .

[25]  B. H. Blott,et al.  The determination of magnetic moments of extended samples in a SQUID magnetometer , 1993 .

[26]  W. Goree,et al.  Some Techniques for Sensitive Magnetic Measurements Using Superconducting Circuits and Magnetic Shields , 1967 .

[27]  J. Rebouillat.  High resolution automatic magnetometer using a superconducting magnet: Application to high field susceptibility measurements , 1972 .

[28]  M. W. Garrett,et al.  Axially Symmetric Systems for Generating and Measuring Magnetic Fields. Part I , 1951 .

[29]  T. J. Summer.  A calculation of the effect of a coaxial superconducting shield on the magnetic field distribution of an enclosed coaxial solenoid , 1987 .

[30]  G. Crabtree,et al.  A low field SQUID magnetometer system for magnetic characterization of high‐Tc superconducting samples , 1991 .

[31]  P. Huray,et al.  Micromagnetic susceptometer. [4. 2 to 300 K] , 1980 .

[32]  F. Kissell,et al.  Apparatus for the Determination of Magnetothermodynamic Properties to High Fields at Low Temperatures Utilizing a Superconducting Magnet , 1968 .

[33]  D. A. Vincent,et al.  Magnetic susceptibility measurements using a superconducting magnetometer , 1974 .

[34]  E. Day.  DETECTION OF NMR USING A JOSEPHSON-JUNCTION MAGNETOMETER. , 1972 .

[35]  P. Weiss,et al.  Aimantation et phénomène magnétocalorique du nickel , 1925 .

[36]  C. O'connor,et al.  Crystal structures of A2FeCl5⋅H2O (A=Rb+, Cs+) and field dependent superconducting susceptometer measurements , 1979 .

[37]  C. Chappert,et al.  A fully automated SQUID magnetometer for low-field measurements on magnetic very thin films , 1985 .

[38]  L. R. Edwards,et al.  Vibrating Sample Magnetic Image Effects in an Nb3Sn Solenoid , 1970 .

[39]  A. Rowley,et al.  A SQUID-based high pressure magnetic susceptometer , 1987 .

[40]  M. Cerdonio,et al.  Superconducting magnetometer for high resolution susceptibility measurements , 1975 .

[41]  S. Foner,et al.  Detection coil, sensitivity function, and sample geometry effects for vibrating sample magnetometers , 1982 .

[42]  O. Symko,et al.  Calibration of SQUID magnetometer for dilute alloy studies. , 1979, The Review of scientific instruments.

[43]  F. Pipkin,et al.  Magnetically Shielded Solenoid with Field of High Homogeneity , 1965 .

[44]  D. Sullivan,et al.  Magnetic Studies of Oxidized Impurities in Pure Copper Using a SQUID System | NIST , 1974 .

[45]  M. Odehnal,et al.  Observation of higher order NMR larmor lines by SQUID in solids at low magnetic field , 1988 .

[46]  J. Claassen.  Coupling considerations for SQUID devices , 1975 .

[47]  B. H. Blott,et al.  Superconducting screening of flux linked between a SQUID pick-up coil and a coaxial cylindrical sample , 1988 .

[48]  T. Smith.  Magnetic fields produced by a hollow superconducting cylinder and a coaxial solenoid , 1973 .

[49]  S. Williamson,et al.  Uniaxial stress device for use with a SQUID magnetometer , 1985 .

[50]  J. P. Savicki.  Johnson noise in SQUID magnetometers , 1986 .

[51]  H.J.M. ter Brake,et al.  Elimination of flux-transformer crosstalk in multichannel SQUID magnetometers , 1986 .

[52]  Risto J. Ilmoniemi,et al.  SQUID magnetometers for low-frequency applications , 1989 .

[53]  J. P. Harrison,et al.  SQUID magnetometer designed for high Tc superconductors , 1991 .