Magnetic frustration and paramagnetic state transport anomalies in Ho4RhAl and Er4RhAl: Possible test cases for newly identified roles of itinerant electrons
arXiv:2107.04981 · doi:10.1016/j.jmmm.2021.168285
Abstract
We report the results of magnetic, heat-capacity, electrical and magnetoresistance measurements on Ho4RhAl and Er4RhAl, characterized by 3 sites for rare-earths (R). Antiferromagnetic ordering sets in at (T_N =) about 8.8 and 4.0 K respectively. While Ho compound appears to enter into a complex spin-glass phase at T less thanT_N (at nearly 5 K), spin-glass component appears to set in essentially almost at T_N for the Er case. The loss of the spin-disorder contribution in the magnetically ordered state is not pronounced, mimicking that in Gd2PdSi3, a compound which now attracts interest in the area of topological Hall effect and magnetic skyrmions, indicating complex Fermi surface. There is a minimum in the temperature dependence of electrical resistivity in the case of only Ho above T_N, but significant negative magnetoresistance is observed over a wide temperature range in the paramagnetic state increasing with decreasing temperature for both the cases. This finding establishes that these compounds belong to a select group of intermetallics in which spin-disorder contribution apparently increases gradually as one approaches respective TN with decreasing temperature. This could be an experimental signature for the effect due to classical spin-liquid above T_N. In view of these properties analogous to those of Gd2PdSi3, it is of interest to investigate these 4:1:1 compounds further to understand possible unconventional roles of itinerant electrons, not only in the magnetically ordered state but also in the paramagnetic state, predicted by some theories in recent years for which this Gd compound is considered to be a classic example.Besides, magnetoresistance and isothermal entropy change (magnetocaloric effect) track each other.
15 pages, 9 figures
References in corpus (6)
- Slow Magnetic Order-Order Transition in the Spin Chain Antiferromagnet Ca3Co2O6
- Electronic structure and nesting-driven enhancement of the RKKY interaction at the magnetic ordering propagation vector in Gd2PdSi3 and Tb2PdSi3
- Magnetic behavior of metallic kagome lattices, Tb3Ru4Al12 and Er3Ru4Al12
- Anisotropic re-entrant spin-glass features in a metallic kagome lattice, Tb3Ru4Al12
- A report of (topological) Hall anomaly two decades ago in Gd2PdSi3, and its relevance to the history of the field of Topological Hall Effect due to magnetic skyrmions
- Magnetic behavior of new compounds, Gd3RuSn6 and Tb3RuSn6