We present the magnetic properties of complete solid solutions of ZnCr2O4 and CoCr2O4: two well-studied oxide spinels with very different magnetic ground states. ZnCr2O4, with non-magnetic d10 cations occupying the A site and magnetic d3 cations on the B site, is a highly frustrated antiferromagnet. CoCr2O4, with magnetic d7 cations (three unpaired electrons) on the A site as well, exhibits both N\'eel ferrimagnetism as well as commensurate and incommensurate non-collinear magnetic order. More recently, CoCr2O4 has been studied extensively for its polar behavior which arises from conical magnetic ordering. Gradually introducing magnetism on the A site of ZnCr2O4 results in a transition from frustrated antiferromagnetism to glassy magnetism at low concentrations of Co, and eventually to ferrimagnetic and conical ground states at higher concentrations. Real-space Monte-Carlo simulations of the magnetic susceptibility suggest that the first magnetic ordering transition and features of the susceptibility across x are captured by near-neighbor self- and cross-couplings between the magnetic A and B atoms. We present as a part of this study, a method for displaying the temperature dependence of magnetic susceptibility in a manner which helps distinguish between compounds possessing purely antiferromagnetic interactions from compounds where other kinds of ordering are present.
@article{arxiv.0808.3789,
title = {Magnetic phase evolution in the spinel compounds Zn$_{1-x}$Co$_x$Cr$_2$O$_4$},
author = {Brent C. Melot and Jennifer E. Drewes and Ram Seshadri and Arthur P. Ramirez},
journal= {arXiv preprint arXiv:0808.3789},
year = {2009}
}