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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.

The zero-field moment of Tb has been determined at 4.2 K for a very pure single crystal along the b direction. A value of (9.490 ± 0.010) μ B /at was found. The corresponding conduction electron polarization of 0.519 μ B /at is much higher than previously estimated. The conduction electron susceptibility was found not to be at variance with the value obtained from band calculations. No agreement is found for the field dependence of the magnetization at 64.5 K and 77 K with a renormalized spin wave theory although the differences are small.

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.

A sample of YBa 2 Cu 3 O 7 was constructed by stacking a number of small single crystals. Magnetization measurements were made in magnetic fields up to 38 T, both parallel to the c -axis and to the basal plane. At 1.4, 4.2 and 20.4 K, a large irreversible magnetization was observed. The significance of these results for the superconducting properties is discussed.

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 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.

Magnetization measurements in pulsed magnetic fields up to 40 T at 1.3, 67 and 78K have been performed on a 50 mg sample composed of 45 aligned single crystals of YBa2Cu3O7. Data have been obtained with the applied field both parallel and perpendicular to the c axis. The results are compared with dc magnetization measurements on the same sample. At high temperature a strong dependence on the field sweep velocity is observed. The results are discussed in terms of flux pinning and thermally activated flux-flow.

De Haas-van Alphen oscillations have been observed in the magnetization of a power sample of ln3 Yb and are ascribed to a small spherical part of the Fermi surface.

The non-linearity of the magnetization of Pd at 4.2°K has been determined in semi-continuous fields up to 325 kOe. The value of β in the expression M = χ H (1 + βH 2 ) is found to be positive, β = (9.5 ± 1.7) × × 10 −18 m 2 /A 2 ≙ 6 × 10 −14 Oe −2 .