Abstract
The dimensionality of the electronic and magnetic structure of a given material is generally predetermined by its crystal structure. Here, using elastic and inelastic neutron scattering combined with magnetization measurements, we find unusual magnetic behavior in three-dimensional (3D) Ba2CoO4. In spite of isolated CoO4 tetrahedra, the system exhibits a 3D noncollinear antiferromagnetic order in the ground state with an anomalously large Curie-Weiss temperature of 110 K compared to TN=26 K. More unexpectedly, spin dynamics displays quasi-two-dimensional spin-wave dispersion with an unusually large spin gap, and one-dimensional magnetoelastic coupling. Our results indicate that Ba2CoO4 is a unique system for exploring the interplay between isolated polyhedra, low-dimensional magnetism, and spin states in oxides.
| Original language | English |
|---|---|
| Article number | 094416 |
| Journal | Physical Review B |
| Volume | 99 |
| Issue number | 9 |
| DOIs | |
| State | Published - Mar 14 2019 |
Funding
We would like to thank Zhentao Wang and Sándor Tóth for helpful discussions. This work was primarily supported by the US Department of Energy under EPSCoR Grant No. DE-SC0012432 with additional support from the Louisiana Board of Regents. Use of the high-flux isotope reactor at the Oak Ridge National Laboratory was supported by the US Department of Energy, Office of Basic Energy Sciences, Scientific User Facilities Division.
| Funders | Funder number |
|---|---|
| Office of Basic Energy Sciences | |
| US Department of Energy | |
| Office of Experimental Program to Stimulate Competitive Research |