The magnetic properties of amorphous Fe$ sb{ rm x}$T$ sb{ rm 100-x}$ (T = Zr, Hf, Sc; 89 $ le$ x $ le$ 93) alloys have been systematically studied mainly by Mossbauer spectroscopy and magnetization measurements. Two magnetic transitions have been observed in Fe$ sb{92.5}$Hf$ sb{7.5}$ (the only FeHf alloys studied here) and FeZr alloys with Fe content between 90 and 93 at.%. We have ruled out the cluster models which attribute the second transition either to the ordering of AFM clusters or to the freezing of FM clusters, and confirmed that the second transition is due to the homogeneous freezing of the transverse spin components as a result of exchange frustration. On varying the frustration level, the evolution process from a ferromagnetic to a spin glass ordering has been observed. Fe$ sb{89}$Zr$ sb{11}$ essentially exhibits conventional ferromagnetic behavior, while Fe$ sb{90}$Zr$ sb{10}$ shows two magnetic transitions with a noncollinear ground state. As we increase the Fe content further (and thus raise the frustration level), the second transition temperature T$ sb{xy}$ and the noncollinearity of the ground state increase, whereas the first transition temperature T$ sb{c}$ drops. T$ sb{xy}$ and T$ sb{c}$ are expected to meet at x $ simeq$ 94.5, suggesting that Fe$ sb{94.5}$Zr$ sb{5.5}$ (which can not be made by melt-spinning) would be a spin glass. Fe$ sb{91}$Sc$ sb9$ is the most frustrated system studied here and it exhibits a single transition to a spin glass. Extrapolation of the magnetic properties of all systems gives a common limit as the Fe concentration approaches 100%, and suggests that amorphous Fe is a spin glass with the spin freezing temperature about 100K and an average iron moment of $ sim$1.6$ mu sb{B}$. Below the second transition, the transverse spin components are strongly correlated on a nearest neighbor scale in Fe$ sb{92}$Zr$ sb7$Sn, while the correlation length of the longitudinal components shows no detectable change on the local scal
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.41224 |
| Date | January 1993 |
| Creators | Ren, Hong, 1962- |
| Contributors | Ryan, D. H. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Physics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001357653, proquestno: NN91703, Theses scanned by UMI/ProQuest. |
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