Noncentrosymmetric Nowotny Chimney Ladder Ferromagnet Cr4Ge7 with a High Curie Temperature of ∼207 K
Noncentrosymmetric magnets usually host intriguing magnetic interactions inherent in 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 (P4̅c2, 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 μB 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-like behavior at ∼18 K is assumed to arise from a competition between the Dzyaloshinskii-Moriya and Heisenberg interactions. The results provide an excellent platform for the study of intricate interactions among various magnetic exchanges as well as for the exploration of high-temperature exotic magnetic properties.
2-s2.0-85199067920
ShanghaiTech University
Beijing Normal University
ShanghaiTech University
Ningbo Institute of Industrial Technology, Chinese Academy of Sciences
Beijing Normal University
ShanghaiTech University
ShanghaiTech University
ShanghaiTech University
Harbin Institute of Technology
Institute of Physics Chinese Academy of Sciences
2024
REVIEWED
EPFL
| Funder | Funding(s) | Grant Number | Grant URL |
ShanghaiTech University | |||
CAS | |||
DOE Office of Science | |||
| Show more | |||