| dc.contributor.author | Yewondwossen, Mammo H. | en_US |
| dc.date.accessioned | 2014-10-21T12:37:13Z | |
| dc.date.available | 1995 | |
| dc.date.issued | 1995 | en_US |
| dc.identifier.other | AAINN08822 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55096 | |
| dc.description | A systematic and quantitative study of the electronic properties of the magnetically ordered $\rm Al\sb{70-x}Pd\sb Mn\sb B\sb{x}\ (x=0$, 2, 4, 6, 8, 10) icosahedral quasicrystalline alloys under the combined influences of externally applied electric and magnetic fields and the internal quasiperiodic potential due to ionic quasilattice is the subject of this thesis. | en_US |
| dc.description | Results from the measurement of the temperature dependence of the magnetic susceptibility indicates re-entrant magnetic behaviour. The temperature dependence of the resistivity has been measured between 4 and 300K. At low temperature, T $<$ 30 K, the resistivity showed a rapid decrease with increasing temperature. Weak localization and magnetic scattering effects describe the temperature dependence of the resistivity in this temperature range. At higher temperatures the resistivity is adequately described by the temperature dependence of the structural and magnetic contributions to the resistivity. | en_US |
| dc.description | The transverse magnetoresistance is measured in fields up to $5.5\ T$ at different temperatures between 4.2 and $28\ K$. The magnetoresistance consists of a superposition of the weak localization contribution and a negative classical spin disorder scattering at local magnetic moments. The results showed a systematic change as a function of boron concentration. The magnetoresistance for $\rm x<6$ showed a negative field dependence which became weak with increasing x. The samples with $\rm x=8$, 10 showed a positive magnetoresistance. The analysis of the results has been based on the theory of three-dimensional weak localization. | en_US |
| dc.description | The present Hall resistivity measurement $\rho\sb{H}$ show that $\rho\sb{H}$ is the result of two contributions; the normal and anomalous. The normal Hall coefficient is independent of temperature in all the alloys and it passes from negative to positive with increasing Boron concentration. This is explained by the effects of s-d hybridization. The anomalous Hall coefficient ($R\sb{s}$) is also found to be temperature independent. The compositional dependence of $R\sb{s}$ showed a systematic change with increasing x and this chance is correlated with that of the spin-orbit scattering rate obtained from the magnetoresistance measurement and this suggests that the anomalous Hall effect is spin-orbit interaction induced. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1995. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Physics, Condensed Matter. | en_US |
| dc.subject | Engineering, Materials Science. | en_US |
| dc.title | Electron transport in aluminum(70-x) palladium(15) manganese(15) boron(x) quasicrystals. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
