The nature of the magnetic order in Ca3Co2O6

TL;DR

This study investigates the magnetic ordering in Ca3Co2O6 using neutron diffraction, revealing a complex coexistence of long-range and short-range magnetic orders that evolve with temperature.

Contribution

It provides a detailed characterization of the magnetic structure and interactions in Ca3Co2O6, highlighting the coexistence and temperature dependence of different magnetic orders.

Findings

Magnetic order sets in below 25 K with a modulated structure.

Long-range magnetic order coexists with short-range order in the material.

Short-range order volume increases as temperature decreases.

Abstract

We present a detailed powder and single crystal neutron diffraction study of the spin chain compound Ca3Co2O6. Below 25 K, the system orders magnetically with a modulated partially disordered antiferromagnetic structure. We give a description of the magnetic interactions in the system which is consistent with this magnetic structure. Our study also reveals that the long-range magnetic order co-exists with a shorter range order with a correlation length scale of 180 A in the ab plane. Remarkably, on cooling, the volume of material exhibiting short range order increases at the expense of the long-range order.