Magnetic ground state and perturbations of the distorted kagome Ising metal TmAgGe
| Autor: | Larsen, C. B., Mazzone, D. G., Gauthier, N., Rosales, H. D., Albarracín, F. A. Gómez, Lass, J., Boraley, X., Bud'ko, S. L., Canfield, P. C., Zaharko, O. |
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| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Phys. Rev. B 107, 224419 (2023) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevB.107.224419 |
| Popis: | We present the magnetic orders and excitations of the distorted kagome intermetallic magnet TmAgGe. Using neutron single crystal diffraction we identify the propagation vectors $\bf{k}$ = (1/2 0 0) and $\bf{k}$ = (0 0 0) and determine the magnetic structures of the zero-field and magnetic field-induced phases for $H$ along the $a$ and [-1 1 0] crystal directions. We determine the experimental magnetic field-temperature ($H$, $T$)-phase diagram and reproduce it by Monte-Carlo simulations of an effective spin exchange Hamiltonian for one distorted kagome layer. Our model includes a strong axial single-ion anisotropy and significantly smaller exchange couplings which span up to the third-nearest neighbours within the layer. Single crystal inelastic neutron scattering (INS) measurements reveal an almost flat, only weakly dispersive mode around 7 meV that we use alongside bulk magnetization data to deduce the crystal-electric field (CEF) scheme for the Tm$^{3+}$ ions. Random phase approximation (RPA) calculations based on the determined CEF wave functions of the two lowest quasi-doublets enable an estimation of the interlayer coupling that is compatible with the experimental INS spectra. No evidence for low-energy spin waves associated to the magnetic order was found, which is consistent with the strongly Ising nature of the ground state. Comment: 16 pages, 12 figures, accepted for publication in Phys. Rev. B |
| Databáze: | arXiv |
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