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S Kaprzyk

Publications and source records attributed to S Kaprzyk.

7 recordsLinked to original sources

Anomalous electronic correlations in the ground state momentum density of Al(97)Li(3).

We report high resolution Compton scattering measurements on an Al(97)Li(3) disordered alloy single crystal for momentum transfer along the [100], [110], and [111] symmetry directions. The results are interpreted via corresponding Korringa-Kohn-Rostoker coherent potential approximation first-principles computations. By comparing spectra for Al(97)Li(3) and Al, we show that the momentum density in the alloy differs significantly from the predictions of the conventional Fermi-liquid picture and that the ground state of Al is modified anomalously by the addition of Li.

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Temperature-dependent orbital degree of freedom of a bilayer manganite by magnetic compton scattering.

We have measured temperature-dependent magnetic Compton profiles (MCPs) from a single crystal of La1.2Sr1.8Mn2O7. The MCPs, which involved the scattering of circularly polarized x rays, are in general related to the momentum density of all the unpaired spins in the system. Nevertheless, we show that when the x-ray scattering vector lies along the [110] direction, the number of magnetic electrons of a specific symmetry, i.e., d electrons of x(2)-y(2) symmetry, yield a distinct signature in the MCP, allowing us to monitor substantial changes in the occupancy of the dx(2)(-y(2)) states over the investigated temperature range of 5-200 K. This study indicates that magnetic Compton scattering can provide a powerful window on the properties of specific magnetic electrons in complex materials.

Journal Article↗