Magnetic excitations in the spin-5/2 antiferromagnetic trimer substance SrMn3P4O14

TL;DR

This study investigates magnetic excitations in SrMn3P4O14, revealing weakly dispersive excitations consistent with a spin-5/2 trimer model, confirmed through inelastic neutron scattering experiments.

Contribution

The paper provides experimental validation of the spin-5/2 trimer model in SrMn3P4O14 using inelastic neutron scattering, quantifying intra-trimer interactions.

Findings

Weak dispersion of magnetic excitations observed.

Excitations correspond to transitions between discrete energy levels.

Intra-trimer interaction J1 estimated at 0.29 meV.

Abstract

A quantum-mechanical 1/3 magnetization plateau and magnetic long-range order appear in the large-spin (5/2) substance SrMn3P4O14. Magnetization results of SrMn3P4O14 can be explained by the spin-5/2 isolated antiferromagnetic linear trimer with the intra-trimer interaction ($J_1$) value of 4.0 K. In the present study, to confirm the spin system, we performed inelastic neutron scattering (INS) experiments of SrMn3P4O14 powders. We observed plural magnetic excitations. The peak positions are 0.46, 0.68, and 1.02 meV. Constant-Q-scan spectra at several Q values (magnitude of the scattering vector) indicate that the dispersion is weak. The weak dispersion indicates that the excitations are transitions between discrete energy levels. Our INS results are consistent with results expected in the trimer model. We evaluated the J1 value as 0.29 meV (3.4 K) without considering the other interactions.