| Автор | N Cao |
| Автор | T Timusk |
| Автор | N P Raju |
| Автор | J E Greedan |
| Автор | P Gougeon |
| Дата выпуска | 1995-03-20 |
| dc.description | The temperature dependence of the reflectance of the spin glass materials R<sub>2</sub>Mo<sub>2</sub>O<sub>7- delta </sub> (R: Sm, Gd, and Ho) has been measured for frequencies from 40 to 40 000 cm<sup>-1</sup> The AC conductivity of Sm<sub>2</sub>Mo<sub>2</sub>O<sub>7- delta </sub> derived from Kramers-Kronig analysis, indicates a Drude-like behaviour as the temperature is lowered. Between 150 and 40 K the scattering rate shows a sharp drop which is attributed to the scattering of conduction electrons by short-range ordered moments of the Mo ions. Below the spin glass transition temperature T<sub>f</sub> ( approximately=40 K) the scattering rate saturates due to the freezing of the moments. Gd<sub>2</sub>Mo<sub>2</sub>O<sub>7- delta </sub> behaves like a poor metal at room temperature, but at low temperatures shows a linear increase in the conductivity for frequencies up to 400 cm<sup>1</sup> suggesting a localized hopping conductivity. The localization remains in the spin glass state for T<T<sub>f</sub> ( approximately=25 K). The conductivity of Ho<sub>2</sub>Mo<sub>2</sub>O<sub>7- delta </sub> is semiconductor-like with a small and slightly temperature-dependent gap around 0.25 eV. Our optical results support a qualitative band model proposed by Sleight and Bouchard for the pyrochlore oxides. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | Optical properties of pyrochlore oxides R<sub>2</sub>Mo<sub>2</sub>O<sub>7- delta </sub> (R: Sm, Gd, and Ho) |
| Тип | paper |
| DOI | 10.1088/0953-8984/7/12/013 |
| Electronic ISSN | 1361-648X |
| Print ISSN | 0953-8984 |
| Журнал | Journal of Physics: Condensed Matter |
| Том | 7 |
| Первая страница | 2489 |
| Последняя страница | 2506 |
| Аффилиация | N Cao; Dept. of Phys., McMaster Univ., Hamilton, Ont., Canada |
| Аффилиация | T Timusk; Dept. of Phys., McMaster Univ., Hamilton, Ont., Canada |
| Аффилиация | N P Raju; Dept. of Phys., McMaster Univ., Hamilton, Ont., Canada |
| Аффилиация | J E Greedan; Dept. of Phys., McMaster Univ., Hamilton, Ont., Canada |
| Аффилиация | P Gougeon; Dept. of Phys., McMaster Univ., Hamilton, Ont., Canada |
| Выпуск | 12 |
