Dielectric anomalies in CoCr$_2$O$_4$

We investigate the magnetic,dielectric, and thermodynamic properties of CoCr$_2$O$_4$ polycrystalline samples. AC susceptibility and specific heat measurements show the existence of two distinct magnetic transitions in this material. Neutron scattering experiments confirm a ferrimagnetic ordering transition at T$_c$=95 K and a transition to a spiral magnetic phase below T$_N$~25 K. We observe a significant dielectric anomaly coincident with the onset to long-range spiral magnetic order, and a separate feature with significant thermal hysteresis above T=50 K. We associate this higher temperature dielectric anomaly with short-range spiral magnetic order, and discuss these results in the context of utilizing magnetodielectric couplings to capacitively probe short range magnetic structures.