| Autor: |
Vinay Gupta, K. Sreenivas, Aparna Saxena |
| Rok vydání: |
2004 |
| Předmět: |
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| Zdroj: |
Journal of Crystal Growth. 263:192-202 |
| ISSN: |
0022-0248 |
| DOI: |
10.1016/j.jcrysgro.2003.10.083 |
| Popis: |
Single crystals of phosphoric acid (H 3 PO 4 ) doped triglycine sulfate (TGSP) are grown from aqueous solution containing 10–50 mol% of H 3 PO 4 . Large sized crystals of dimension (70 mm×40 mm×25 mm) suitable for IR detector applications are obtained with 20 mol% of H 3 PO 4 . They exhibit elongated domains, and the domain density is higher than in undoped TGS crystals. FT-IR analysis indicates the presence of both zwitter and glycinium ions in the doped TGSP crystals, which is due to the low incorporation of H 3 PO 4 into the TGS crystal lattice. The dielectric properties TGSP crystals measured in the temperature range 27–65°C and in frequency range 102–105 Hz show a broad transition, and the peak dielectric constant values are reduced with increasing H 3 PO 4 concentration. Hysteresis loops with high coercive fields are observed up to 20 mol% of H 3 PO 4 . At a higher concentration, double loops are observed due to the polarization switching inhibition by H 3 PO 4 molecules. Dopant concentration is found to have a marginal influence on the spontaneous polarization of the TGSP crystals. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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