[Zurück]

M. El-Hagary, H. Michor, M. Wind, E. Bauer, G. Hilscher, P. Rogl:
"Magnetic behavior of LaCo_13-xSi_x in the vicinity of the critical concentration x=4";
Journal of Alloys and Compounds, 367 (2004), S. 239 - 245.

Abstract

Magnetic, specific heat and transport studies on the solid solution LaCo13-xSix (x=3.8, 3.9, 4.0, 4.1, and 4.5) imply the existence of a critical composition xcrit=4 for the onset of magnetism. For alloys on the Co-rich side (x<4) magnetic susceptibility measurements reveal weak ferromagnetism with a decrease of TC with increasing x . These magnetic phase transitions are also seen in the electrical resistivity and specific heat measurements. At the stoichiometric composition with x=4, namely for LaCo9Si4, we observe full structural order within the space group I4/mcm, but magnetic order appears to be absent. LaCo9Si4 shows spin fluctuation behavior, which persists on the silicon-rich side x>4. Resistivity, susceptibility and specific heat measurements on LaCo9Si4 provide strong indication for the presence of spin fluctuations with a T2 temperature dependence of the electrical resistivity, an enhanced low temperature Pauli susceptibility [small chi, Greek] 0LT [approximately equal to] 47×10-3 emu/mol at 2 K and a large Sommerfeld value [small gamma, Greek] =200 mJ/(mol K2).

Author Keywords: Author Keywords: Intermetallic; X-ray diffraction; Heat capacity; Magnetic properties

http://aleph.ub.tuwien.ac.at/F?base=tuw01&func=find-c&ccl_term=AC04970015

http://dx.doi.org/10.1016/j.jallcom.2003.08.045