| Автор | R Mallik |
| Автор | E S Reddy |
| Автор | P L Paulose |
| Автор | Subham Majumdar |
| Автор | E V Sampathkumaran |
| Дата выпуска | 1999-05-31 |
| dc.description | We present the results of measurements of the electrical resistivity (), magnetoresistance (MR) and dc and ac susceptibility () of polycrystalline samples of the type La<sub>0.5</sub>Ca<sub>0.5-x</sub>Ba<sub>x</sub>MnO<sub>3</sub>, synthesized under identical heat-treatment conditions. The substitution of larger Ba ions for Ca results in a non-monotonic variation of the Curie temperature (T<sub>C</sub>) as the system evolves from a charge-ordered insulating state for x = 0.0 to a ferromagnetic metallic state for x = 0.5. An intermediate composition, that with x = 0.1, interestingly exhibits ferromagnetic, insulating behaviour with thermal hysteresis in the ac at around the Curie temperature (T<sub>C</sub> = 120 K). The x = 0.2 and 0.3 compounds exhibit semiconducting-like behaviour as the temperature is lowered below 300 K, with a broad peak in at around 80-100 K; these compositions exhibit a weak increase in as the temperature is lowered below 30 K, indicative of electron localization effects; these compositions also undergo ferromagnetic transitions below about 200 and 235 K respectively, though these are non-hysteretic; most significantly, for these compositions, the MR is large and conveniently measurable over the entire temperature range of measurement below T<sub>C</sub> and this experimental finding may be of interest from the applications point of view. We infer that the A-site ionic-size mismatch plays a crucial role in determining these properties. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | Transport and magnetic anomalies due to A-site ionic-size mismatch in La<sub>0.5</sub>Ca<sub>0.5-x</sub>Ba<sub>x</sub>MnO<sub>3</sub> |
| Тип | paper |
| DOI | 10.1088/0953-8984/11/21/306 |
| Electronic ISSN | 1361-648X |
| Print ISSN | 0953-8984 |
| Журнал | Journal of Physics: Condensed Matter |
| Том | 11 |
| Первая страница | 4179 |
| Последняя страница | 4188 |
| Аффилиация | R Mallik; Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400 005, India |
| Аффилиация | E S Reddy; Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400 005, India |
| Аффилиация | P L Paulose; Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400 005, India |
| Аффилиация | Subham Majumdar; Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400 005, India |
| Аффилиация | E V Sampathkumaran; Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai-400 005, India |
| Выпуск | 21 |
