Distinct order of Gd 4f and Fe 3d moments coexisting in GdFe4Al8

Single crystals of flux-grown tetragonal GdFe4Al8 were characterized by thermodynamic, transport, and x-ray resonant magnetic scattering measurements. In addition to antiferromagnetic order at TN ~ 155 K, two low-temperature transitions at T1 ~ 21 K and T2 ~ 27 K were identified. The Fe moments order at TN with an incommensurate propagation vector (tau,tau,0) with tau varying between 0.06 and 0.14 as a function of temperature, and maintain this order over the entire T<TN range. The Gd 4f moments order below T2 with a ferromagnetic component mainly out of plane. Below T1, the ferromagnetic components are confined to the crystallographic plane. Remarkably, at low temperatures the Fe moments maintain the same modulation as at high temperatures, but the Gd 4f moments apparently do not follow this modulation. The magnetic phase diagrams for fields applied in [110] and [001] direction are presented and possible magnetic structures are discussed.Comment: v2: 14 pages, 12 figures; PRB in prin

Distinct order of Gd 4f and Fe 3d moments coexisting in GdFe4Al8

Single crystals of flux-grown tetragonal GdFe4Al8 were characterized by thermodynamic, transport, and x-ray resonant magnetic scattering measurements. In addition to antiferromagnetic order at T(N)approximate to 155 K, two low-temperature transitions at T(1)approximate to 21 K and T(2)approximate to 27 K were identified. The Fe moments order at T-N with an incommensurate propagation vector (tau,tau,0) with tau varying between 0.06 and 0.14 as a function of temperature, and maintain this order over the entire T < T-N range. The Gd 4f moments order below T-2 with a ferromagnetic component mainly out of plane. Below T-1, the ferromagnetic components are confined to the crystallographic plane. Remarkably, at low temperatures the Fe moments maintain the same modulation as at high temperatures, but the Gd 4f moments apparently do not follow this modulation. The magnetic phase diagrams for fields applied in [110] and [001] direction are presented and possible magnetic structures are discussed.This article is published as Angst, M., A. Kreyssig, Y. Janssen, J-W. Kim, L. Tan, D. Wermeille, Y. Mozharivskyij, A. Kracher, A. I. Goldman, and P. C. Canfield. "Distinct order of Gd 4 f and Fe 3 d moments coexisting in Gd Fe 4 Al 8." Physical Review B 72, no. 17 (2005): 174407. DOI: 10.1103/PhysRevB.72.174407. Copyright 2005 American Physical Society. Posted with permission