Spin glass anomalies in stoichiometric spin-chain oxides, Ca3CoXO6 (X = Rh, Ir and Co)

TL;DR

This study investigates ac susceptibility in Ca3CoXO6 compounds, revealing unusual spin-glass behavior with large frequency dependence near magnetic transition temperatures, attributed to geometrical frustration in stoichiometric materials.

Contribution

It demonstrates that Ca3CoXO6 compounds are unconventional spin-glasses with frequency-dependent ac susceptibility following Vogel-Fulcher behavior, due to geometrical frustration.

Findings

Large frequency dependence of ac susceptibility near magnetic transitions

Vogel-Fulcher relationship observed in peak temperature dependence

Unusual spin-glass behavior in stoichiometric compounds

Abstract

The results of ac susceptibility (chi) measurements for Ca3CoXO6 (X = Rh, Ir and Co) compounds, containing spin-chains separated by Ca ions, are presented. All these compounds exhibit an unusually large frequency dependence of ac chi, in the vicinity of respective magnetic ordering temperatures, which is normally not encountered in conventional spin-glasses. The frequency dependence of ac chi, peak temperature is however found to obey Vogel-Fulcher relationship. The results thus establish that these compounds are unusual spin-glasses, that too among stoichiometric compounds presumably due to geometrical frustration.