Dielectric anomalies and spiral magnetic order in CoCr2O4
By Gavin Lawes, B. Melot, Katharine L. Page, C. Ederer, Michael A. Hayward, T. Proffen, Ram Seshadri. 2006
171 citations recorded by the source corpus.
We have investigated the structural, magnetic, thermodynamic, and dielectric properties of polycrystalline CoCr2O4, an insulating spinel exhibiting both ferrimagnetic and spiral magnetic structures. Below Tc=94 K the sample develops long-range ferrimagnetic order, and we attribute a sharp phase transition at TS27 K to the onset of long-range spiral magnetic order. Neutron measurements confirm that the structure remains cubic at 80 K and at 11 K; the magnetic ordering by 11 K is seen to be rather complex. Density functional theory supports the view of a ferrimagnetic semiconductor with magnetic interactions consistent with noncollinear ordering. Capacitance measurements on CoCr2O4 show a sharp decrease in the dielectric constant at TS, but also an anomaly showing thermal hysteresis falling between approximately T=50 and 57 K. We tentatively attribute the appearance of this higher-temperature dielectric anomaly to the development of short-range spiral magnetic order, and discuss these results in the context of utilizing dielectric spectroscopy to investigate noncollinear short-range magnetic structures.
Subfields: Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Materials Chemistry
View Paper: https://www.semanticscholar.org/paper/bf8a2098510e99123ffdc5e9d9835564e7684409
How researchers see this paper
The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.
In Condensed Matter Physics
In Electronic, Optical and Magnetic Materials
In Materials Chemistry
Citations in the corpus
- Introduction to magnetoelectric coupling and multiferroic films (2011, background): “Although a peak in the dielectric constant typically marks the transition to a ferroelectric phase, some ceramic type-2 multiferroic samples, including CoCr2O4, show a similar sharp decrease in the dielectric constant [252], making it plausible that this feature marks the development of ferroelectri”