Collapse of the magnetic ordering and structural anomalies in the U La S system: neutron diffraction and specific heat measurements.

Autor: Bourdarot, F., Bombardi, A., Burlet, P., Calemczuk, R., Lander, G.H., Lapierre, F., Sanchez, J.P., Mattenberger, K., Vogt, O.
Zdroj: European Physical Journal B: Condensed Matter; Jul1999, Vol. 9 Issue 4, p605-611, 7p
Abstrakt: We report specific heat and neutron diffraction measurements of seven samples in the solid solution system UxLa1-xS. All samples have the simple fcc NaCl crystal structure. Both specific heat and neutron diffraction confirm the suggestion from the earlier magnetic measurements that the ferromagnetism disappears abruptly at 0.57. Near there is a doubling of the electronic contribution to the specific heat, as compared to the value of 23 mJ mol-1K-2 in pure US. Around the widths of the nuclear Bragg peaks show a considerable broadening, as well as anomalies in the mean lattice parameter, as compared to those expected from Vegard's law. A preliminary analysis suggests this broadening may be due to a loss of long range lattice order near . However, these changes are independent of temperature, so that further experiments are necessary before they can be associated with the changes in magnetic behavior at . [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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