Spin Density wave instability in a ferromagnet

Yan Wu; Zhenhua Ning; Huibo Cao; Guixin Cao; K. A. Benavides; Gregory T. McCandless; R. Jin; Julia Y. Chan; W. A. Shelton; J. F. DiTusa

arXiv · 1704.06727

Spin Density wave instability in a ferromagnet

Yan Wu·Zhenhua Ning·Huibo Cao·Guixin Cao·K. A. Benavides·Gregory T. McCandless·R. Jin·Julia Y. Chan·W. A. Shelton·J. F. DiTusa

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Abstract

Ferromagnetic (FM) and incommensurate spin-density wave (ISDW) states are an unusual set of competing magnetic orders that are seldom observed in the same material without application of a polarizing magnetic field. We report, for the first time, the discovery of an ISDW state that is derived from a FM ground state through a Fermi surface (FS) instability in Fe$_3$Ga$_4$. This was achieved by combining neutron scattering experiments with first principles simulations. Neutron diffraction demonstrates that Fe$_3$Ga$_4$ is in an ISDW state at intermediate temperatures and that there is a conspicuous re-emergence of ferromagnetism above 360 K. First principles calculations show that the ISDW ordering wavevector is in excellent agreement with a prominent nesting condition in the spin-majority FS demonstrating the discovery of a novel instability for FM metals; ISDW formation due to Fermi surface nesting in a spin-polarized Fermi surface.

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Yan Wu, Zhenhua Ning, Huibo Cao, Guixin Cao, K. A. Benavides, Gregory T. McCandless, R. Jin, Julia Y. Chan, W. A. Shelton, J. F. DiTusa. 2017-07-25. Spin Density wave instability in a ferromagnet. https://arxiv.org/abs/1704.06727

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