Incommensurate magnetic ground state revealed by RXS in the frustrated spin system Ca3Co2O6

TL;DR

This study uses resonant x-ray scattering to uncover an incommensurate, partially disordered antiferromagnetic ground state in Ca3Co2O6, revealing complex magnetic ordering phenomena in a frustrated spin system.

Contribution

It provides the first direct evidence of an incommensurate magnetic ground state in Ca3Co2O6 using RXS, highlighting temperature-dependent magnetic modulation and correlation length behavior.

Findings

Abrupt magnetic transition below 25 K

Magnetic correlation length exceeds 5500 Å

Temperature-dependent modulation in magnetic order

Abstract

We have performed a resonant x-ray scattering study at the Co pre-K edge on a single crystal of Ca3Co2O6. The measurements reveal an abrupt transition to a magnetically ordered state immediately below T_N = 25 K, with a magnetic correlation length in excess of 5500 {\AA} along the c-axis chains. There is no evidence for modifications to the Co$^{3+}$ spin state. A temperature dependent modulation in the magnetic order along the c-axis and an unusual decrease in the magnetic correlation lengths on cooling are observed. The results are compatible with the onset of a partially disordered antiferromagnetic structure in Ca3Co2O6.