Thermodynamic Investigation of Metamagnetic Transitions and Partial Disorder in the Quasi-Kagome Kondo Lattice CePdAl

Abstract

Low-temperature ($T$) thermodynamic properties in magnetic fields ($B$) of the quasi-Kagome antiferromagnet CePdAl ($T_{\mathrm{N}}\sim$ 2.7 K) were studied by means of magnetization and specific-heat $C(T,B)$ measurements. The unusual magnetic phase diagram, including three thermodynamic phases I-III, and crossover anomalies, has been obtained. In low-field phase I, the existence of the partial Kondo screening state on the one-third Ce sites is supported from the thermodynamic point of view: (i) an appearance of the paramagnetic moment with one-third of the full moment around 3 T, and (ii) an occurrence of the entropy release $\sim$0.3$R$ln2 around the observed crossover. On the other hand, a strong enhancement of $C/T$ is found around the point, where $T_{\mathrm{N}}(B)$ meets the boundary of phase III, indicating the possible presence of a tri-critical point. Furthermore, it is suggested that the three metamagnetic transitions at $B_{\mathrm{m}i}$ ($i=$1,2,3) come from successive increments of the Ising-type magnetic moment along the $c$-axis. In high-field state above 20 T, the behavior of $f$ electron can be rather described by the crystal-electric-field model.

6 pages, 5 figures

References in corpus (3)

• Divergence of the Magnetic Grüneisen Ratio at the Field-Induced Quantum Critical Point in YbRh${}_2$Si${}_2$
• Temperature-field phase diagram of geometrically frustrated CePdAl
• Nematic order in the multiple-spin exchange model on the triangular lattice

Cited by in corpus (1)

• Evolution of the partially frustrated magnetic order in CePd${}_{1-x}$Ni${}_x$Al