Twofold enhancement of the hidden-order/large-moment antiferromagnetic phase boundary in the URu2-xFexSi2 system.

Electrical resistivity, specific heat, and magnetization measurements on URu2-xFexSi2 reveal a twofold enhancement of the "hidden-order" (HO)/large-moment antiferromagnetic (LMAFM) phase boundary T0(x). The T0(Pch) curve, obtained by converting x to "chemical pressure" Pch, is strikingly similar to the T0(P) curve, where P is applied pressure, for URu2Si2 both exhibit a "kink" at 1.5 GPa and a maximum at ~7 GPa. This similarity suggests that the HO-LMAFM transition at 1.5 GPa in URu2Si2 occurs at x ≈ 0.2 (Pch ≈ 1.5 GPa) in URu2-xFexSi2. URu2-xFexSi2 provides an opportunity for studying the HO and LMAFM phases with methods that probe the electronic structure [e.g., scanning tunneling microscopy (STM), angle-resolved photoemission spectroscopy (ARPES), and point-contact spectroscopy (PCS)] but cannot be used under pressure. [ABSTRACT FROM AUTHOR]