Speaker
Mr
Jan Zubáč
(Katedra fyziky kondenzovaných látek, Matematicko-fyzikální fakulta Univerzity Karlovy v Praze)
Description
We have investigated magnetic properties of the intermetallic NdPd$_5$Al$_2$ compound by means of specific heat and magnetization measurements, neutron diffraction and inelastic neutron scattering. The compound crystallizes in the tetragonal $I4/mmm$ space group with lattice parameters $a=$4.147 A and $c=$14.865 A, orders antiferromagnetically below $T_{\mathrm{N}}= $1.3 K and presents large magnetocrystalline anisotropy due to the crystal-field effects. The magnetic phase diagram constructed on the basis of specific heat and magnetization measurements is characterized by two distinct magnetically ordered phases similarly to structurally related tetragonal $RTX_5$ and $R_2TX_8$ compounds. The zero-field antiferromagnetic phase is characterized by the propagation vector $k = (\frac{1}{2} 0 0)$ and antiferromagnetic coupling of Nd moments along the tetragonal $c$-axis with the amplitude of magnetic moments of 2.22 $\mu_{\mathrm{B}}$/Nd as was revealed by neutron diffraction. The transition from the paramagnetic to magnetically ordered phase in zero field is the first-order phase transition. The crystal-field excitations in NdPd$_5$Al$_2$ were detected by means of inelastic neutron scattering at 3.0 meV, 7.4 meV, 8.6 meV and 17.1 meV. We further compare our findings about crystal field in NdPd$_5$Al$_2$ obtained from inelastic neutron scattering, susceptibility analysis and first-principles calculations and confront them with the experimental magnetization and magnetic specific heat data.
| Sekce | Fyzika kondenzovaných látek |
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Primary author
Mr
Jan Zubáč
(Katedra fyziky kondenzovaných látek, Matematicko-fyzikální fakulta Univerzity Karlovy v Praze)
