Anomalies of inverse direct current susceptibility in spin-chain compounds Ca3Co2-xMnxO6.

Various types of anomalies of inverse dc susceptibility (H/M) have been observed in spin-chain compounds Ca3Co2-xMnxO6. For x = 1.0, the H/M curve exhibits a field-dependent downturn from the paramagnetic Curie-Weiss behavior, signaling the presence of a Griffiths-like cluster phase. A slight decrease of x leads to a rapid suppression of the Griffiths-like singularity, followed by an appearance of field-independent, non-Griffiths-like behavior at x = 0.92. This feature persists until x = 0.33, at and below which the H/M curve presents an unambiguous, field-independent upturn from the Curie-Weiss law. These Mn-doping-dependent anomalies of H/M curves are associated with complex competing magnetic interactions. [ABSTRACT FROM AUTHOR]