- Petr Král: Physical properties of Ce2Pd2In under external pressure
- 11. 12. 2019, 14:10
- lecture room F2, first floor Ke Karlovu 5
- more information
Abstract:
The physics of rare-earth-based intermetallics is mainly determined by highly correlated 4f-electrons. In some compounds usually localized 4f-electrons states can hybridize with the wave functions of neighboring atoms. The unique way how to directly affect the interatomic distances and thus the hybridization is application of external pressure.
In our study we have focused on the cerium-based compound Ce2Pd2In, which is known to crystallize in the Mo2FeB2-type structure (space group P 4/m b m), in the Shastry-Sutherland lattice consisting of planes formed by Ce-atoms alternated by non-magnetic planes containing other elements. It belongs to the group of Ce2T2In compounds exhibiting well-localized magnetism (Ce2Cu2In, Ce2Au2In, Ce2Pd2In) or valence fluctuations (Ce2Ni2In, Ce2Rh2In) [1,2], depending on the d-band of the transition metal T.
The magnetic ground state of this compound is very sensitive to the off-stoichiometry. The excess of Ce leads to ferromagnetic ground state, while the excess of Pd results in an incommensurate antiferromagnetism with propagation vector k = (0.22, 0, 0). The accurate stoichiometry leads to presence of two magnetic transitions, the compound reaches ordered ferromagnetic ground state through the intermediate antiferromagnetic state [3,4,5].
We present new results of ambient pressure characterization of the high quality Ce2Pd2In single crystal and the magnetic behavior of the compound with respect to the external pressure application. Under hydrostatic pressure up to 3 GPa, antiferromagnetic phase remains to significantly lower temperatures. Extension of the experiment to higher pressure range is needed to estimate total suppression of the ferromagnetic ground state. In frame of another experiment, the uniaxial pressure was applied along the crystallographic c-axis in order to affect directly the anisotropy of the lattice. We found that the saturated magnetization is decreasing with increase of the pressure, while the positions of phase transitions aren’t affected significantly.
References:
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[2] R. Hauser, H. Michor et al., Physica B 1997, 230, 211.
[3] M. Giovannini, H. Michor et al, Phys. Rev. B 2000, 61, 4044
[4] D. Kaczorowski, M. Giovannini et al., Czech. J. Phys. 1996, 46, 2063
[5] M. Klicpera, S. Maskova et al., J. Magn. Magn. Mater. 2016, 404, 250