Tuning the magnetic ground state of a triangular lattice system

TL;DR

This study investigates how doping affects the magnetic ground state in a triangular lattice system, revealing transitions from long-range order to two-dimensional order and changes in magnetic coupling.

Contribution

It provides new insights into tuning magnetic ground states via doping in a frustrated antiferromagnet with a triangular lattice.

Findings

Doping alters the magnetic coupling from antiferromagnetic to ferromagnetic.

Structural distortion influences the stabilization of long-range magnetic order.

Increased doping suppresses structural distortion and reduces magnetic dimensionality.

Abstract

The anisotropic triangular lattice of the crednerite system Cu(Mn1-xCux)O2 is used as a basic model for studying the influence of spin disorder on the ground state properties of a two-dimensional frustrated antiferromagnet. Neutron diffraction measurements show that the undoped phase (x=0) undergoes a transition to antiferromagnetic long-range order that is stabilized by a frustration-relieving structural distortion. Small deviation from the stoichiometric composition alters the magnetoelastic characteristics and reduces the effective dimensionality of the magnetic lattice. Upon increasing the doping level, the interlayer coupling changes from antiferromagnetic to ferromagnetic. As the structural distortion is suppressed, the long-range magnetic order is gradually transformed into a two-dimensional order.