Magnetic excitations at the Brillouin zone boundary in Mn (17%Fe, 3%Cu) alloy
Abstract
In tetragonal Mn (18%Cu) and Mn (13.7%Ni) alloys the low and medium energy excitations were observed previously near points at the magnetic Brillouin-zone (MBZ) boundary, geometrically equivalent to the MBZ centre. The properties of the inelastic neutron scattering (INS) on these excitations, e.g. the temperature dependence of its intensity, are different from those of spin waves observed near the MBZ centre. The nature of these excitations is not yet clearly understood. Here, the magnetic excitations at the MBZ boundary in the Mn (17%Fe, 3%Cu) alloy are investigated. In our sample, (68+/-8)% of the volume is occupied by domains with the c-axis oriented along one direction. The INS at the MBZ centre increases when the temperature is lowered. It is dominated by the spin waves but a small quasi-elastic scattering is also present. The INS intensity at the MBZ boundary shows a very weak temperature dependence.
- Publication:
-
Physica B Condensed Matter
- Pub Date:
- July 2004
- DOI:
- 10.1016/j.physb.2004.03.022
- Bibcode:
- 2004PhyB..350E..79J
- Keywords:
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- Magnetic excitations;
- Manganese alloys;
- Antiferromagnetism