An automatic device for measurements of the magnetic moment in high d.c. magnetic fields up to 20 T produced by a Bitter coil is presented. The extraction technique is used and a cryostat associated to a calorimeter permits us to cover the 1.4–500 K temperature range. The calibration, the accuracy and the sensitivity of the system are discussed.

Automatic device for precise magnetic measurements in high continuous magnetic fields

High field magnetization measurements have been used to determine the critical current densities Jc(H.T) of single crystals from the Bean model and the anisotropy of the magnetic moment in the normal state.

Critical current densities (up to 20 T) of high Tc REBa2Cu3O7, Bi2Sr2CaCu2O8, Tl2Ba2CaCu2O8 crystals

Magnetization measurements were performed on single crystals fo ErBa 2 Cu 3 O 7 and HoBa 2 Cu 3 O 7 in magnetic fields up to 180 kOe applied parallel to the c -axis or in the ( ab ) plane in the 4.2–200 K temperature range. From isothermal hysteresis cycles the anisotropy of both critical current density and paramagnetic rare-eart were deduced.

High magnetic field properties of ErBa2Cu3O7 and HoBa2Cu3O7 single crystals

http://ieeexplore.ieee.org/iel2/828/2820/00689905.pdf

Magnetic properties of Gd Ba Cu Qz single crystals in high magnetic field

The magnetic properties of single crystals of GdBa/sub 2/Cu/sub 3/O/sub 7/ were investigated in a magnetic field of up to 20 T applied parallel to the c axis in the 1.7-300 K temperature range. In the superconducting state, the field and temperature dependences of the critical current densities were deduced from the hysteresis of the half-cycle using Bean's critical state model. The Gd/sup 3+/ paramagnetic moment was then studied. Above about 20 K, the M(H) isotherms were found to be given, at different temperatures, by the Brillouin function of the free Gd/sup 3+/ ion. Below 20 K, the average magnetization does not obey the Brillouin law. The normal-state susceptibility was described by the free-ion Curie-Weiss law. >

J.C. Levet

Papers

High magnetic field properties of ErBa2Cu3O7 and HoBa2Cu3O7 single crystals

Magnetic properties of Gd Ba Cu Qz single crystals in high magnetic field

Magnetic properties of GdBa/sub 2/Cu/sub 3/O/sub 7/ crystals in high magnetic field