Single-Crystal Neutron Structural Analyses of Potassium Dihydrogen Phosphate and Potassium Dideuterium Phosphate
| Autor: | Yukio Noda, Tatsuki Miyoshi, Hiroyuki Mashiyama, Hiroyuki Kimura, Takanao Asahi |
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| Rok vydání: | 2011 |
| Předmět: |
Materials science
Potassium Neutron diffraction Analytical chemistry General Physics and Astronomy chemistry.chemical_element Hydrogen atom Ferroelectricity Potassium dideuterium phosphate Condensed Matter::Materials Science chemistry.chemical_compound Deuterium chemistry Kinetic isotope effect Physics::Atomic Physics Single crystal |
| Zdroj: | Journal of the Physical Society of Japan. 80:044709 |
| ISSN: | 1347-4073 0031-9015 |
| DOI: | 10.1143/jpsj.80.044709 |
| Popis: | Single-crystal neutron structural analyses have been performed on both potassium dihydrogen phosphate (KDP) and potassium dideuterium phosphate (DKDP) in order to discuss the isotope effect from structural viewpoints. The values of spontaneous polarization are calculated from the refined structural parameters by the point-charge method, and the calculated values are almost in good agreement with the experimental values of each compound. The temperature dependences of the anisotropic atomic displacement parameters U 33 's and positional shifts of potassium, phosphorus, oxygen, and hydrogen/deuterium atoms along the polar c -axis is compared between KDP and DKDP. It is concluded that the paraelectric-ferroelectric transitions are perfectly of the improper order–disorder type in both KDP and DKDP; the ordering of the hydrogen atom induces the spontaneous displacements of both potassium and phosphorus atoms. The interatomic distances and angles in the paraelectric and ferroelectric phases of KDP and DKDP are ... |
| Databáze: | OpenAIRE |
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