We report the synthesis of three new Yb-based compounds, Yb8Ag18.5Al47.5 (Yb8Cu17Al49-type, tetragonal tI74?I4/mmm), Yb2Pd2Cd (Mo2B2Fe-type, tetragonal tP10-P4/mbm) and Yb1.35Pd2Cd0.65 (MnCu2Al-type, cubic cF16?Fm3�m). The crystal symmetry of these compounds has been determined and the complete structural characterisation carried out by single crystal and powder diffraction techniques. Two symmetry in-equivalent sites are available for the Yb ions in Yb8Ag18.5Al47.5 and Yb1.35Pd2Cd0.65. The 4f levels of the Yb ions are appreciably hybridised in Yb8Ag18.5Al47.5 and to a lesser extent in Yb2Pd2Cd as inferred from the magnetisation and heat capacity data. Signatures of heavy fermion behaviour are observed in the heat capacity data of Yb2Pd2Cd in which the heat capacity, C/T, increases at low temperatures attaining a value of ?600mJ/molK2 at 1.8K. The electrical resistivity of Yb2Pd2Cd follows a linear variation with temperature, T, between 1.4 and 5K, thus indicating a possible non-Fermi liquid behaviour. In contrast, Yb ions are trivalent in Yb1.35Pd2Cd0.65 and order magnetically near 1.4K.
Synthesis, crystal structure and magnetic properties of Yb8Ag18.5Al47.5, Yb2Pd2Cd and Yb1.35Pd2Cd0.65
MANFRINETTI, PIETRO;PANI, MARCELLA
2007-01-01
Abstract
We report the synthesis of three new Yb-based compounds, Yb8Ag18.5Al47.5 (Yb8Cu17Al49-type, tetragonal tI74?I4/mmm), Yb2Pd2Cd (Mo2B2Fe-type, tetragonal tP10-P4/mbm) and Yb1.35Pd2Cd0.65 (MnCu2Al-type, cubic cF16?Fm3�m). The crystal symmetry of these compounds has been determined and the complete structural characterisation carried out by single crystal and powder diffraction techniques. Two symmetry in-equivalent sites are available for the Yb ions in Yb8Ag18.5Al47.5 and Yb1.35Pd2Cd0.65. The 4f levels of the Yb ions are appreciably hybridised in Yb8Ag18.5Al47.5 and to a lesser extent in Yb2Pd2Cd as inferred from the magnetisation and heat capacity data. Signatures of heavy fermion behaviour are observed in the heat capacity data of Yb2Pd2Cd in which the heat capacity, C/T, increases at low temperatures attaining a value of ?600mJ/molK2 at 1.8K. The electrical resistivity of Yb2Pd2Cd follows a linear variation with temperature, T, between 1.4 and 5K, thus indicating a possible non-Fermi liquid behaviour. In contrast, Yb ions are trivalent in Yb1.35Pd2Cd0.65 and order magnetically near 1.4K.
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
