|
|||||
|
|
Spin moment over 10-300 K and delocalization of magnetic electrons above the Verwey transition in magnetite |
|
| Authors: | Yinwan Li PA Montano B Barbiellini PE Mijnarends S Kaprzyk A Bansil |
| Institution: | a Department of Physics, University of Illinois, Chicago, IL 60680, USA b Materials Science Division, Argonne National Laboratory, Argonne, IL 60439, USA c Scientific User Facilities Division, Basic Energy Sciences, US Department of Energy, 1000 Independence Ave. SW, Washington, DC 20585-1290, USA d Physics Department, Northeastern University, Boston, MA 02115, USA e Department of Radiation, Radionuclides & Reactors, Faculty of Applied Sciences, Delft University of Technology, Delft, The Netherlands f Academy of Mining and Metallurgy AGH, 30059 Kraków, Poland |
| Abstract: | In order to probe the magnetic ground state, we have carried out temperature-dependent magnetic Compton scattering experiments on an oriented single crystal of magnetite (Fe3O4), together with the corresponding first-principles band theory computations to gain insight into the measurements. An accurate value of the magnetic moment μS associated with unpaired spins is obtained directly over the temperature range of 10-300 K. μS is found to be non-integral and to display an anomalous behavior with the direction of the external magnetic field near the Verwey transition. These results reveal how the magnetic properties enter the Verwey energy scale via spin-orbit coupling and the geometrical frustration of the spinel structure, even though the Curie temperature of magnetite is in excess of 800 K. The anisotropy of the magnetic Compton profiles increases through the Verwey temperature Tv and indicates that magnetic electrons in the ground state of magnetite become delocalized on Fe B-sites above Tv. |
| Keywords: | 78 70 Ck 75 50 Gg 71 30 +h |
| 本文献已被 ScienceDirect 等数据库收录！ | |