Half Semimetallic Antiferromagnetism in the Sr$_2$CrTO$_6$ System, T=Os, Ru
| dc.creator | Lee, K. -W. | |
| dc.creator | Pickett, W. E. | |
| dc.date | 2007-12-28 | |
| dc.date.accessioned | 2026-07-07T09:27:48Z | |
| dc.date.available | 2026-07-07T09:27:48Z | |
| dc.description | Double perovskite Sr$_2$CrOsO$_6$ is (or is very close to) a realization of a spin-asymmetric semimetallic compensated ferrimagnet, according to first principles calculations. This type of near-half metallic antiferromagnet is an unusual occurrence, and more so in this compound because the zero gap is accidental rather than being symmetry determined. The large spin-orbit coupling (SOC) of osmium upsets the spin balance (no net spin moment without SOC): it reduces the Os spin moment by 0.27 $μ_B$ and induces an Os orbital moment of 0.17 $μ_B$ in the opposite direction. The effects combine (with small oxygen contributions) to give a net total moment of 0.54 $μ_B$ per cell in \scoo, reflecting a large impact of SOC in this compound. This value is in moderately good agreement with the measured saturation moment of 0.75 $μ_B$. The value of the net moment on the Os ion obtained from neutron diffraction (0.73 $μ_B$ at low temperature) differs from the calculated value (1.14 $μ_B$). Rather surprisingly, in isovalent Sr$_2$CrRuO$_6$ the smaller SOC-induced spin changes and orbital moments (mostly on Ru) almost exactly cancel. This makes Sr$_2$CrRuO$_6$ a "half (semi)metallic antiferromagnet" (practically vanishing net total moment) even when SOC is included, with the metallic channel being a small-band-overlap semimetal. Fixed spin moment (FSM) calculations are presented for each compound, illustrating how they provide different information than in the case of a nonmagnetic material. These FSM results indicate that the Cr moment is an order of magnitude stiffer against longitudinal fluctuations than is the Os moment. | |
| dc.description | 6 pages | |
| dc.identifier | https://arxiv.org/abs/0712.4308 | |
| dc.identifier | http://arxiv.org/abs/0712.4308 | |
| dc.identifier | Phys. Rev. B 77, 115101 (2008) | |
| dc.identifier | doi:10.1103/PhysRevB.77.115101 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/157237 | |
| dc.subject | Materials Science | |
| dc.subject | Strongly Correlated Electrons | |
| dc.title | Half Semimetallic Antiferromagnetism in the Sr$_2$CrTO$_6$ System, T=Os, Ru | |
| dc.type | text |