Frustrated antiferromagnetic spin chains of edge-sharing tetrahedra in volcanic minerals K3Cu3(Fe0.82Al0.18)O2(SO4)4 and K4Cu4O2(SO4)4MeCl

TL;DR

This paper investigates the magnetic interactions in two volcanic minerals, revealing they are quasi-one-dimensional frustrated antiferromagnets with unique magnetic structures influenced by their crystal configurations.

Contribution

It provides the first detailed calculation of magnetic interactions in these specific minerals, highlighting their frustrated spin chains and electric polarization effects.

Findings

Both minerals are quasi-one-dimensional frustrated antiferromagnets.

Strong antiferromagnetic couplings within chains and weak between chains.

Presence of electric polarization in piipite's tetrahedral chains.

Abstract

The calculation of the sign and strength of magnetic interactions in two noncentrosymmetric minerals (klyuchevskite, K3Cu3(Fe0.82Al0.18)O2(SO4)4 and piipite, K4Cu4O2(SO4)4Cu0.5Cl) has been performed based on the structural data. As seen from the calculation results, both minerals comprise quasi-one-dimensional frustrated antiferromagnets. They contain frustrated spin chains from edge-sharing Cu4 tetrahedra with strong antiferromagnetic couplings within chains and very weak ones between chains. Strong frustration of magnetic interactions is combined with the presence of the electric polarization in tetrahedra chains in piipite. The uniqueness of magnetic structures of these minerals caused by peculiarities of their crystal structures has been discussed. Keywords: Frustrated quasi-one-dimensional antiferromagnets, tetrahedral spin chains, klyuchevskite K3Cu3(Fe0.82Al0.18)O2(SO4)4, piypite K4Cu4O2(SO4)4MeCl