Satellite holmium M-edge spectra from the magnetic phase via resonant x-ray scattering

Developing an expression of resonant x-ray scattering (RXS) amplitude which is convenient for investigating the contributions from the higher rank tensor on the basis of a localized electron picture, we analyze the RXS spectra from the magnetic phases of Ho near the $M_{4,5}$ absorption edges. At the $M_5$ edge in the uniform helical phase, the calculated spectra of the absorption coefficient, the RXS intensities at the first and second satellite spots capture the properties the experimental data possess, such as the spectral shapes and the peak positions. This demonstrates the plausibility of the adoption of the localized picture in this material and the effectiveness of the spectral shape analysis. The latter point is markedly valuable since the azimuthal angle dependence, which is one of the most useful informations RXS can provides, is lacking in the experimental conditions. Then, by focusing on the temperature dependence of the spectral shape at the second satellite spot, we expect that the spectrum is the contribution of the pure rank two profile in the uniform helical and the conical phases while that is dominated by the rank one profile in the intermediate temperature phase, so-called spin slip phase. The change of the spectral shape as a function of temperature indicates a direct evidence of the change of magnetic structures undergoing. Furthermore, we predict that the intensity, which is the same order observed at the second satellite spot, is expected at the fourth satellite spot from the conical phase in the electric dipolar transition.Comment: 24 pages, 5 figure

Thermo-Physical and Physical Properties for Use in Solidification Modelling of Multi-Component Alloys

International audienceThe thermo-physical and physical properties of the liquid and solid phases are critical components in casting simulations. Such properties include the fraction solid transformed, enthalpy release, thermal conductivity, volume and density, all as a function of temperature. Due to the difficulty in experimentally determining such properties at solidification temperatures, little information exists for multi-component alloys. As part of the development of a new computer programme for modelling of materials properties, JMatPro, extensive work has been carried out on the development of sound, physically based models for these properties. Wide-ranging results have previously been presented for Fe, Ni, Ti, Al and Mg-based alloys. The purpose of the present paper is to look at how changes in composition can substantially affect properties of multi-component alloys during solidification and further demonstrate how properties of the liquid can substantially vary in the mushy zone

Modelling of materials properties and behaviour critical to casting simulation

Abstract Thermo-physical and physical properties of liquid and solid phases during solidification are critical data for casting simulations. However, the number of alloys for which such information is available is limited, primarily due to the difficulty in experimentally determining these properties during the casting/solidification process. Because small variations in composition can have marked effects, it is unwise to extrapolate properties derived from other alloys. The purpose of this paper is to demonstrate the value of integrating the modelling of solidification and the associated thermo-physical and physical properties for multi-component alloys, using Java-based materials properties software (JMatPro). This includes how changes in the composition of an alloy within its specification range can substantially affect its properties during solidification and how properties of the liquid can vary significantly in the mushy zone

4f orbital and spin magnetism in cerium intermetallic compounds studied by magnetic circular x-ray dichroism

none6Schillé, J.; Bertran, F.; Finazzi, Marco; Brouder, C. h.; Kappler, J.; Krill, G.J., Schillé; F., Bertran; Finazzi, Marco; Brouder, C. h.; J., Kappler; G., Kril