The Collinear Magnetic Phases of the Geometrically-Frustrated Antiferromagnet CuFeO$_2$: The Importance of Stacking

TL;DR

This study accurately determines exchange and anisotropy parameters of CuFeO$_2$ by analyzing stacking effects, revealing the stability of collinear magnetic phases and identifying the magnetic unit cell through spin-wave frequency fits.

Contribution

It introduces precise stacking considerations to estimate magnetic parameters and identifies the magnetic unit cell of a specific phase in CuFeO$_2$.

Findings

Stacking significantly affects magnetic parameter estimates.

The collinear phase is stable between 13.5 and 20 T.

The magnetic unit cell of the $udd$ phase contains two layers and 10 Fe$^{3+}$ spins.

Abstract

The correct stacking of hexagonal layers is used to obtain accurate estimates for the exchange and anisotropy parameters of the geometrically-frustrated antiferromagnet CuFeO$_2$. Those parameters are highly constrained by the stability of a collinear metamagnetic phase between fields of 13.5 and 20 T. Constrained fits of the spin-wave frequencies of the collinear $\uudd $ phase below 7 T are used to identify the magnetic unit cell of the metamagnetic $\uuudd $ phase, which contains two hexagonal layers and 10 Fe$^{3+}$ spins.