Noncentrosymmetric Nowotny Chimney Ladder Ferromagnet Cr4Ge7 with a High Curie Temperature of ~ 207 K

Abstract

Noncentrosymmetric magnets usually host intriguing magnetic interactions inherent the crystal structure with broken inversion symmetry, which can give rise to rich magnetic behaviors. We report herein the high-pressure synthesis, crystal structure, magnetizations and magnetic structure of a so-called Nowotny chimney ladder compound Cr4Ge7. Our analysis on the powder neutron diffraction data revises the crystal structure as a noncentrosymmetric space group (P-4c2, No.116). It exhibits two magnetic orders within the temperature range of 2 - 400 K. The first order at ~ 207 K associated with a small magnetic moment of ~ 0.75 miuB is assigned to a commensurate ferromagnetic structure with a propagation vector k = (0, 0, 0). The weak itinerant ferromagnet nature should be caused by the complex Cr spin orders from different Wyckoff positions. The second order at ~ 18 K is assumed to arise from a competition between the Dzyaloshinskii-Moria and Heisenberg interactions. The results provide an excellent platform for study on intricate interactions between various magnetic exchanges as well as for the exploration of high temperature exotic magnetic properties which host potential applications in next-generation spintronics.

21 pages, 5 figures, 2 tables; Supporting Information is not included

References in corpus (9)

• Electric Field Effect in Atomically Thin Carbon Films
• A new class of chiral materials hosting magnetic skyrmions beyond room temperature
• Controlling many-body states by the electric-field effect in a two-dimensional material
• Room temperature 2D ferromagnetism in few-layered 1$T$-CrTe${}_2$
• Néel-type skyrmion lattice in tetragonal polar magnet VOSe${}_2$O${}_5$
• Room-temperature sub-100 nm Néel-type skyrmions in non-stoichiometric van der Waals ferromagnet $\mathrm{F}{\mathrm{e}}_{3-\mathrm{x}}\mathrm{GaT}{\mathrm{e}}_2$ with ultrafast laser writability
• Spin-Triplet Superconductivity in K2Cr3As3
• Complex itinerant ferromagnetism in noncentrosymmetric Cr11Ge19
• Topological Hall effect and the magnetic states of Nowotney chimney ladder compound Cr${}_{11}$Ge${}_{19}$}