Structural and magnetic properties of antiferromagneticCe2IrGa12

Abstract

We report a study of the structural and magnetic properties of single crystals of Ce2IrGa12. Ce2IrGa12 crystallizes in a layered tetragonal structure, and undergoes an antiferromagnetic transition below 3.1 K. We characterize the temperature-field phase diagrams of Ce2IrGa12 for fields both within the ab-plane and along the c-axis, where the presence of a field-induced magnetic phase is found for in-plane fields. The ordering temperature is moderately enhanced upon the application of pressures up to 2.3 GPa, suggesting that Ce2IrGa12 corresponds to the well localized region of the Doniach phase diagram. PACS number(s): 71.45.Lr, 74.10.+v

Magnetic properties of the layered heavy-fermion antiferromagnetCePdGa6

“…3(a), where γ = 121.4 mJ/mol K 2 was fixed, yielding SW = 2.3 K and c = 23 mJ/mol K 2 . The moderate value of SW is smaller than T N , unlike the layered heavy-fermion gallides Ce 2 PdGa 12 and Ce 2 IrGa 12 , where SW > T N [24,25], likely reflecting the weaker magnetocrystalline anisotropy in CePdGa 6 . The temperature dependence of the magnetic entropy S m of CePdGa 6 is also displayed in Fig.…”

“…On the other hand, at 4 K, the magnetization changes smoothly with field, reaching the same saturated magnetization, indicating that, at this temperature, the spins continuously rotate in the applied field. Such a change with temperature may be a consequence of only a moderate magnetocrystalline anisotropy, as also evidenced by the relatively small value of the spin-wave gap SW /T N ≈ 0.4 as compared with the other heavy-fermion gallides Ce 2 IrGa 12 and Ce 2 PdGa 12 , which have SW /T N of 1.5 and 2.8, respectively [24,25].…”

“…In the case of the layered Ce 2 MGa 12 compounds, the T N of Ce 2 NiGa 12 and Ce 2 PdGa 12 decrease with pressure, and antiferromagnetism is suppressed entirely >5.5 and 7 GPa, respectively [26,27]. On the other hand the T N of Ce 2 IrGa 12 undergoes a moderate enhancement from 3.1 to 3.7 K for pressures up to 2.3 GPa, indicating that this compound is located on the left side of the Doniach phase diagram [25]. In the case of CePdGa 6 , the robustness of T N suggests that measurements to higher pressures are required to situate this compound within the framework of the Doniach phase diagram and to examine whether there is pressure-induced quantum criticality in CePdGa 6 .…”

“…A more layered structure is realized in the Ce 2 MGa 12 (M = Cu, Ni, Rh, Pd, Ir, or Pt) series, where the Ce layers are alternately separated by four Ga layers and units of MGa 6 , leading to a larger interlayer separation of the Ce atoms [20,21]. Several members of this series show evidence for both antiferromagnetism and heavy-fermion behavior [20][21][22][23][24][25], where pressure can readily suppress the antiferromagnetic transitions of Ce 2 NiGa 12 and Ce 2 PdGa 12 [26,27], while evidence for field-induced critical fluctuations is revealed in Ce 2 IrGa 12 [25].…”