Fractional magnetization plateaus in the Shastry–Sutherland lattice material Er2Be2GeO7

The experimental study of magnetism on the Shastry-Sutherland lattice (SSL) has been ongoing for more than two decades, following the discovery of the first SSL material SrCu₂(BO₃)₂. However, investigation of SSL systems is often complicated by the requirements of high magnetic fields (e.g.>20 T for SrCu₂(BO₃)₂) or the presence of itinerant electrons (e.g. REB₄). In this paper, we present the magnetic properties of the SSL material Er₂Be₂GeO₇. Like SrCu₂(BO₃)₂, Er₂Be₂GeO₇exhibits fractional magnetization plateaus. However, unlike SrCu₂(BO₃)₂, Er₂Be₂GeO₇exhibits long-range order below∼1 K, and the plateaus are accessible using commercial laboratory equipment, occurring for fields<1 T. The fractions of magnetization present are closest to1/4,4/9, and1/2of the saturation magnetization. Hysteresis is observed in the4/9and1/2plateau phases. The lack of itinerant electrons, chemical disorder, and the low fields required to access the fractional magnetization plateaus promise Er₂Be₂GeO₇as a prime candidate for the study of frustrated magnetism on the SSL.