Spin waves near the edge of halogen substitution induced magnetic order in Ni(Cl$_{1-x}$Br$_x$)$_2$$\cdot$4SC(NH$_2$)$_2$

A. Mannig; K. Yu. Povarov; J. Ollivier; A. Zheludev

doi:10.1103/PhysRevB.98.214419

paper

Spin waves near the edge of halogen substitution induced magnetic order in Ni(Cl $_{1 - x}$ Br $_{x}$ ) $_{2}$ $\cdot$ 4SC(NH $_{2}$ ) $_{2}$

arXiv:1810.10912 · doi:10.1103/PhysRevB.98.214419

Abstract

We report an inelastic neutron scattering study of magnetic excitations in a quantum paramagnet driven into a magnetically ordered state by chemical substitution, namely Ni(Cl $_{1 - x}$ Br $_{x}$ ) $_{2}$ $\cdot$ 4SC(NH $_{2}$ ) $_{2}$ with $x = 0.21 (2)$ . The measured spectrum is well accounted for by the generalized spin wave theory (GSWT) approach [M. Matsumoto and M. Koga, [J. Phys. Soc. Jap. 76, 073709 (2007)]. This analysis allows us to determine the effective Hamiltonian parameters for a direct comparison with those in the previously studied parent compound and `underdoped' system. The issue of magnon lifetimes due to structural disorder is also addressed.

8 pages, 7 figures

Spin waves near the edge of halogen substitution induced magnetic order in Ni(Cl1−x​Brx​)2​⋅4SC(NH2​)2​

Abstract

Spin waves near the edge of halogen substitution induced magnetic order in Ni(Cl $_{1 - x}$ Br $_{x}$ ) $_{2}$ $\cdot$ 4SC(NH $_{2}$ ) $_{2}$