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Magnetization measurements have been performed on samples composed of oriented YBa 2 Cu 3 O 7 single crystals 1.4 K, 68 K and 78 K in magnetic fields up to 38 T applied along the c -axis and within the ab -plane. The critical currents are deduced from the irreversible magnetization and discussed in terms of pinning forces. At low temperature (1.4 K), the experimental data with the field along the c -axis are compared with a theoretical model for the field dependence of the pinning force. At higher temperatures (68 K and 78 K), the pinning force can be described by a Kramer-like scaling law: F p = A [ B 0 ( T )] m b p (1− b ) q , where B 0 is the field where the irreversibility of the magnetization disappears and where b (= B / B 0 ) is the reduced field. For the exponent m , the usual value of 2.5 is found; approximate values for p and q are around 2 and 4, respectively.

Two constraints on semi-continuous magnet coils are the strength of the winding material, and the maximum power which the rectifier must deliver for a short time. Here we assume that for a 60-T coil wire of sufficient strength (about 100 kg/mm2 is available. It was shown earlier that a single, homogeneous coil needs a power of nearly 150 MW, which calls for huge capital investments in power lines, transformers, switches and rectifiers. By using two nested coils, wound from wires with different strengths and current densities, and energized successively by the same rectifier, we can reduce the power to less than 50 MW.

High field (30 MA m-1) magnetization measurement at 4.2K and 20.4K on samarium single crystals are reported together with low field studies from 1.8K to 130K. The susceptibility results are analyzed in terms of independent contributions from the moments on the cubic and hexagonal sites (which order antiferromagnetically at 14K and 109K respectively), plus a temperature independent susceptibility. At 4.2K a spin-flop transition on the cube sites was observed around 21.6 MA m-1. Using one anisotropy and two exchange parameters a molecular field model correctly describes the main features of the behaviour on the cubic sites, and their saturation moment is calculated to be 0.47 mu B/atom.

The Fermi surface of Nb/sub 3/Sn has been derived from an APW band calculation. de Haas-van Alphen (dHvA) oscillations have been observed in Nb/sub 3/Sn and V/sub 3/Si which give a consistent FS description. Using single crystals of high resistance ratio's and magntic fields up to 400 kOe, dHvA oscillations have been seen in the normal state for both specimens. New features of the Fermi surface include osculated ellipsoidal structure around M and a large cubical structure around LAMBDA.

The magnetization of bismuth single crystals has been measured in very high magnetic fields up to 340 kG. Along the binary and the bisectrix axes the data (at 1.5 K) show small but significant deviations from linearity, but along the trigonal axis the deviation is much smaller and barely significant.

The magnetization of high- T c superconducting REBa 2 Cu 3 O 7 compounds, where RE is Y or one of the rare-earth elements Eu, Gd, Dy, Ho, Er or Yb, has been measured in fields up to 29 T. Though the precise analysis of the data is hampered by the incomplete penetration of the magnetic field due to the shielding-current effect of the superconductivity, the magnetism associated with the rare-earth ions can reasonably be interpreted by crystal-field effects. All of the samples investigated were confirmed to be superconducting at 4.2 K in fields as high as 29 T.

The de Haas-van Alphen (DHVA) effect has been investigated in Pd and Pd-Ni alloys in magnetic fields extending to 40 T. With increasing Ni content, the incipient ferromagnetism gives rise to an unusual behaviour which is dominated by a field dependence of the Stoner factor.

de Haas-van Alphen (dHvA) oscillations have been observed in ${\mathrm{Nb}}_{3}$Sn in the (110) plane and in ${\mathrm{V}}_{3}$Si at two orientations using single crystals of high resistance ratio and magnetic fields in excess of ${H}_{c2}$. The dHvA frequency data for ${\mathrm{Nb}}_{3}$Sn can be interpreted as a series of nested ellipsoids centered at $M$, as suggested by a recent high-precision calculation of the ${\mathrm{Nb}}_{3}$Sn Fermi surface.

Magnet coils are investigated which can produce magnetic fields of 15–40 MA/m (200–500 kOe) during working times of the order of 0.1 sec. These fields are suited for measurements in highly conducting materials. The coils are precooled to 20°K or 77°K and the Joule heat is not removed during the pulse. In Sec. I the thermal limitations of this method are reviewed. Plots are given for the optimum dimensions and current densities for coils producing a specified field during a specified time, minimizing the necessary power supply. Details of a magnet constructed along these lines are given. The maximum field produced by this coil, 16 MA/m (200 kOe) during 0.3 sec, however, proved to be determined by mechanical instabilities. These problems are reviewed in Sec. II. Calculations of the Lorentz force and the internal stresses resulting from it were carried out taking the elastic and plastic properties of copper and insulation into account. It is shown theoretically that a magnet stable to 35 MA/m (440 kOe) can be built from hard drawn copper if a reinforcing steel cylinder is used at a certain radius inside the coil.

The magnetization of NdAl 2 single crystals was measured at 4.2, 20.3 and 77 K, in magnetic fields up to 35 tesla applied in the 〈100〉, 〈110〉 and 〈111〉 directions. The magnetization in these directions may be described theoretically, without any fitting, in terms of two cubic crystalline electric field parameters and one molecular field constant which have been taken from inelastic neutron scattering data. 5

The non-linear part of the magnetisation of pure Pd and dilute PdNi alloys (up to 0.56 at.% Ni) was measured in semi-continuous fields up to 35 T. The Ni-doped Pd shows a negative curvature at high fields whilst for pure Pd a small positive curvature was found as in previous measurements. In the alloys the curvature becomes more pronounced for higher Ni concentrations. These effects and their relation to recent DHVA measurements are discussed in this article.

Hall-effect of single-crystalline UPt 3 and U(Pt 0.95 Pd 0.05 ) 3 was measured in magnetic fields up to 38 T. At all investigated temperatures R H is found to decrease with increasing field; at 1.4 and 4.2 K a large peak is found that is attributed to the suppression of antiferromagnetic correlations.