Magnetic order induced by Fe substitution of Al site in the heavy fermion systems alpha-YbAlB4 and beta-YbAlB4

Abstract

beta-YbAlB4 is a heavy fermion superconductor that exhibits a quantum criticality without tuning at zero field and under ambient pressure. We have succeeded in substituting Fe for Al in beta-YbAlB4 as well as the polymorphous compound alpha-YbAlB4, which in contrast has a heavy Fermi liquid ground state. Full structure determination by single crystal X-ray diffraction confirmed no change in crystal structure for both alpha- and beta-YbAlB4, in addition to volume contraction with Fe substitution. Our measurements of the magnetization and specific heat indicate that both alpha-YbAl0.93Fe0.07B4 and beta-YbAl0.94Fe0.06B4 exhibit a magnetic order, most likely of a canted antiferromagnetic type, at $7\sim 9$ K. The increase in the entropy as well as the decrease in the antiferromagnetic Weiss temperature with the Fe substitution in both systems indicates that the chemical pressure due to the Fe substitution suppresses the Kondo temperature and induces the magnetism.

7 pages, 4 figures

References in corpus (5)

• Fermi-liquid instabilities at magnetic quantum phase transitions
• Quantum Criticality in Heavy Fermion Metals
• Quantum Criticality without Tuning in the Mixed Valence Compound beta-YbAlB4
• Layered Kondo lattice model for quantum critical beta-YbAlB4
• Anisotropic heavy Fermi-liquid formation in the valence fluctuating $\alpha$-YbAlB${}_4$

Cited by in corpus (7)

• Strange metal without magnetic criticality
• Pressure-induced magnetic transition exceeding 30 K in the Yb-based heavy fermion superconductor $\beta$-YbAlB${}_4$
• High temperature antiferromagnetism in Yb based heavy fermion systems proximate to a Kondo insulator
• Interpretation of some Yb-based valence-fluctuating crystals as approximants to a dodecagonal quasicrystal
• Quantum critical behaviour and Lifshitz transition in intermediate valence $\alpha$-YbAlB${}_4$
• Quantum Criticality and Inhomogeneous Magnetic Order in Fe-doped alpha-YbAlB4
• Multiband electronic transport in $\alpha$-Yb${}_{1-x}$Sr${}_x$AlB${}_4$ [x = 0, 0.19(3)] single crystals