Speaker
Abstract content <br> (Max 300 words)
The transport and thermodynamic properties of CeTX(T = Au,Cu; X = Ge,Si) compounds have been studied. These well-ordered hexagonal compounds have shown (FM) ordering anomalies in magnetic susceptibility, electrical resistivity and specific heat at FM transition temperature TC, (10K, 10K and 15K for CeAuGe [1], CeCuGe and CeCuSi [2], respectively). The location of magnetic ordering has been observed to be unstable under the influence of applied magnetic field [2], where the FM ordering has been observed to shift upwards in temperature. However, the application of chemical pressure as observed from physical properties as well as magnetic properties measurements revealed a continuous suppression of TC, associated with Ce moments, resulting in the FM transition temperature approaching 0K as La content is increased. The calculation of the effective magnetic moment for small La contents was observed to be 2.54 μB/mol in agreement with the value of the full magnetic moment for Ce3+ ion. Despite the observed suppression of TC, observed in these dilution compounds, it was observed from powder x-ray diffraction characterization that the crystal structures of the compounds were retained as hexagonal belonging to space group number 186 ((Ce1-xLax)AuGe) and 194 for (Ce1-xLax)CuGe and (Ce1-xLax)CuSi. Rietveld refinement profile indicated that the lattice parameters a and c and the volume V of the dilution compounds were increased with the increase in La content. This work presents the first results of the effect of isostructural substitution of Ce with La ((Ce1-xLax)AuGe; (Ce1-xLax)CuGe and (Ce1-xLax)CuSi) having various x contents. Measurements of magnetic susceptibility, electrical resistivity and specific heat for the dilution compounds gave the first evidence of the possibility of non-Fermi liquid behavior as chemical pressure was used to tune ferromagnetism to lower temperatures.
[1] Pӧttgen R, Borrmann H and Kremer R K, 1996 J. Magn. Magn. Mater. 152 196
[2] Yang F, Kuang J P, Li J, Bruck E, Nakotte H, de Boer F R, Wu X, Li Z and Wang Y,
1991 J. Appl. Phys. 69 470
Level for award<br> (Hons, MSc, <br> PhD)?
PhD
Main supervisor (name and email)<br>and his / her institution
Prof. Andre Strydom
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
Yes
Apply to be<br> considered for a student <br> award (Yes / No)?
Yes
