<p>This thesis is focused on the synthesis and structural determination of a series of quasicrystal approximants in the <i>RE</i><sub>13</sub>Zn<sub>~58</sub> (<i>RE</i> = Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu), Ce<sub>13</sub>Cd<sub>~58 </sub>and <i>RE</i>Cd<sub>6</sub> (<i>RE</i> = Tb, Ho, Er, Tm and Lu) systems. Structural studies were performed by single crystal X-ray diffraction methods.</p><p>The <i>RE</i>Cd<sub>6</sub> phases are 1/1 cubic approximants to the stable icosahedral quasicrystals. The structure of quasicrystals cannot be solved by conventional crystallography due to the lack of periodicity in three-dimensional space. On the other hand, quasicrystal approximants exhibit long-range order, which makes their structural determination possible by standard methods. Since they are believed to display the same local arrangement as the quasicrystals, the structures of the quasicrystal approximants play a key role in understanding quasicrystals.</p><p>The <i>RE</i><sub>13</sub>Zn<sub>~58</sub> and Ce<sub>13</sub>Cd<sub>~58</sub> quasicrystal approximants show measurable compositional variations coupled to subtle structural differences. The crystal structures are generally rather more complex than previously reported, and exhibit a number of different ordering and disordering modes.</p>
| Identifer | oai:union.ndltd.org:UPSALLA/oai:DiVA.org:su-7203 |
| Date | January 2007 |
| Creators | Piao, ShuYing |
| Publisher | Stockholm University, Department of Physical, Inorganic and Structural Chemistry, Stockholm : Institutionen för fysikalisk kemi, oorganisk kemi och strukturkemi |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Doctoral thesis, comprehensive summary, text |
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