Nuclear Magnetic Relaxation in the Ferrimagnetic Chain Compound NiCu(C_7_H_6_N_2_O_6_)(H_2_O)_3_2H_2_O: Three-Magnon Scattering?

TL;DR

This paper investigates proton spin-lattice relaxation in a ferrimagnetic chain compound, providing evidence that three-magnon scattering significantly influences relaxation rates, supported by an advanced spin-wave theoretical analysis.

Contribution

It introduces a modified spin-wave theory to explain relaxation times and demonstrates the dominant role of three-magnon scattering over Raman processes in this compound.

Findings

Three-magnon scattering is the main relaxation mechanism.

Modified spin-wave theory accurately explains experimental data.

Raman scattering plays a lesser role in relaxation processes.

Abstract

Recent proton spin-lattice relaxation-time (T_1_) measurements on the ferrimagnetic chain compound NiCu(C_7_H_6_N_2_O_6_)(H_2_O)_3_2H_2_O are explained by an elaborately modified spin-wave theory. We give a strong evidence of the major contribution to 1/T_1_ being made by the three-magnon scattering rather than the Raman one.