Spin-wave spectrum of copper metaborate in the commensurate phase 10K<T<21K

TL;DR

This study investigates the spin-wave spectrum of copper metaborate in the commensurate phase using inelastic neutron scattering, revealing two excitation branches and characterizing exchange interactions within the Cu(A) subsystem.

Contribution

The paper provides the first detailed analysis of spin-wave excitations in copper metaborate's commensurate phase, specifically identifying two branches and determining exchange parameters for Cu(A).

Findings

Two branches of spin-wave excitations identified.

Interaction between Cu(A) and Cu(B) sublattices negligible in 10K-21K.

Exchange parameters for Cu(A)) subsystem determined.

Abstract

We have investigated the spin-wave spectrum of copper metaborate, CuB$_2$O$_4$, by means of inelastic neutron scattering in the commensurate magnetic phase. We have found two branches of spin-wave excitations associated with the two magnetic sublattices Cu(A) and Cu(B), respectively. In the temperature regime $10K \le T \le 21K$, where only the Cu(A) magnetic moments are ordered, the interaction between the two sublattices is found to be negligible. With this approximation we have determined the `easy plane' exchange parameters of the Cu(A) subsystem within standard spin-wave theory.