Neutron diffraction on the diluted magnetic semiconductor tin manganese telluride

In the diluted magnetic semiconductor Sn1-xMnxTe, magnetic ordering occurs at low temperature when the charge carrier density p exceeds a critical value. By means of single-crystal neutron diffraction on samples with x=0.03, p = 7 × 1020 cm-3 and x=0.06, p = 11 × 1020 cm-3, we have shown that this ordered phase is ferromagnetic. For the 6% Mn crystal indications were found for magnetic fluctuations just below the ordering temperature. The experimental results rule out the existence of a (reentrant) spin-glass phase at these Mn concentrations and charge carrier densities

Annealing experiments on and high-temperature behavior of the superconductor yttrium barium copper oxide (YBa2Cu3Ox)

The high temperature behaviour (300–1100 K) of the superconductor YBa2Cu3Ox has been studied by annealing experiments, thermal dilatation, thermogravimetry and measurements of the electrical resistance and thermoelectric power. For the fast oxidation process of this compound, reaction enthalpies between 0.82 and 0.92 eV have been determined, depending on the degree of oxidation. The activation energy for the diffusion of oxygen varies between 0.9 and 1.3 eV

Annealing experiments on and high-temperature behavior of the superconductor yttrium barium copper oxide (YBa2Cu3Ox)

The high temperature behaviour (300–1100 K) of the superconductor YBa2Cu3Ox has been studied by annealing experiments, thermal dilatation, thermogravimetry and measurements of the electrical resistance and thermoelectric power. For the fast oxidation process of this compound, reaction enthalpies between 0.82 and 0.92 eV have been determined, depending on the degree of oxidation. The activation energy for the diffusion of oxygen varies between 0.9 and 1.3 eV