Mode Assignment for Magnetic Excitations Associated with Co2+ Impurities in Antiferromagnetic FeF2
| dc.contributor.author | Donnelly, David W. | |
| dc.date.accessioned | 2010-06-02T10:21:02Z | |
| dc.date.available | 2012-02-24T10:21:02Z | |
| dc.date.issued | 1995-07 | |
| dc.description.abstract | We have performed far-infrared (FIR) absorption and Raman-scattering measurements on the Co-FeF2 system for Co concentrations 0.05 ≤ = x ≤ = 5%, in magnetic fields O ≤ H ≤ 30 kG applied parallel to the crystal c axis. In addition to a careful study of the H dependence of the previously reported impurity associated mode at 85 cm-1, we have observed an impurity-induced shift in the host two-magnon FIR absorption, and an impurity-pair excitation in Raman scattering at a frequency of 223 cm-1. Taken together, these results are shown to be inconsistent with the previous interpretation of the 85 cm-1 mode as being localized on the impurity spin (i.e., an s0 mode). Instead, from a mean-field cluster model, we show that the new observations are only consistent with an assignment of the original resonance to be that of a shell mode (s1). All of the data agrees with this assignment within the framework of the impurity Green's-function theory as well. The 85 cm-1 resonance is, to our knowledge, the first s1 impurity mode to have been observed, a not surprising result when one considers the rather stringent conditions on localization of an s1 mode contained in Tonegawa's Green's-function theory. | |
| dc.description.department | Physics | |
| dc.format | Text | |
| dc.format.extent | 8 pages | |
| dc.format.medium | 1 file (.pdf) | |
| dc.identifier.citation | Donnelly, D. W. (1995). Mode assignment for magnetic excitations associated with Co2+ impurities in antiferromagnetic FeF2. Physical Review B, 52(2), pp. 1042-1049. | |
| dc.identifier.uri | https://hdl.handle.net/10877/4047 | |
| dc.language.iso | en | |
| dc.publisher | American Physical Society | |
| dc.source | Physical Review B, July 1, 1995, Vol. 52, No. 2, pp. 1042-1049. | |
| dc.subject | mode assignment | |
| dc.subject | magnetic excitations | |
| dc.subject | Co2+ impurities | |
| dc.subject | antiferromagnetic | |
| dc.subject | FeF2 | |
| dc.subject | Physics | |
| dc.title | Mode Assignment for Magnetic Excitations Associated with Co2+ Impurities in Antiferromagnetic FeF2 | |
| dc.type | Article |
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