Origin of the low-temperature anomaly in Ce-based approximant crystals

Clarify the origin of the low-temperature peak anomaly in the magnetic susceptibility and specific heat of the Ce-based 1/1 approximant crystals Ag-In-Ce and Au-Al-Ce, including whether it results from spin-glass-like short-range magnetic order.

Background

The paper describes a peak anomaly below 1 K in both the magnetic susceptibility and specific heat of the Ce-based 1/1 approximant crystals Ag-In-Ce and Au-Al-Ce. The negative Curie-Weiss temperature suggests dominant antiferromagnetic interactions, while prior discussion had proposed spin-glass-like short-range magnetic order.

The authors explicitly state that the anomaly’s origin is unresolved and identify it as a motivation for theoretical investigation. The subsequent calculations address magnetic structures in an idealized effective model but do not definitively determine the experimental anomaly’s microscopic origin.

References

The origin of this anomaly is obscure although spin-grass like short-range magnetic order was discussed, which calls for theoretical study.

— Odd-Parity Crystalline Electric Field and Multipoles in Icosahedral Quasicrystal and Approximant: Magnetic Toroidal and Electric Dipoles in Ce-Based Systems  (2610.13009 - Watanabe et al., 9 Oct 2026) in Section Introduction