Crystal structure, dielectric, and optical properties of β-calcium orthophosphates heavily doped with ytterbium
| Autor: | Alexey V. Ishchenko, Ivan I. Leonidov, Bogdan I. Lazoryak, Sergey Yu. Stefanovich, Vladimir A. Morozov, Dina V. Deyneko, Evgeniya S. Zhukovskaya, Alexei A. Belik, O. V. Baryshnikova |
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| Rok vydání: | 2019 |
| Předmět: |
Ytterbium
Phase transition Materials science Mechanical Engineering Metals and Alloys Analytical chemistry chemistry.chemical_element 02 engineering and technology Crystal structure Dielectric 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Ferroelectricity 0104 chemical sciences Differential scanning calorimetry chemistry Mechanics of Materials Materials Chemistry 0210 nano-technology Luminescence Solid solution |
| Zdroj: | Journal of Alloys and Compounds. 787:1301-1309 |
| ISSN: | 0925-8388 |
| DOI: | 10.1016/j.jallcom.2019.02.103 |
| Popis: | Solid solution of Ca10.5–1.5xYbx(PO4)7 (0 ≤ x ≤ 1) was synthesized in the β-Са3(РО4)2-type structure by a standard solid-state method. Second-harmonic generation, differential scanning calorimetry, and dielectric measurements showed the presence of a reversible first-order phase transition of ferroelectric type between the room-temperature polar R3c structure to centrosymmetry. The temperature of the phase transition decreases from 1203 K for x = 0 to 788 K for x = 1, while the second-harmonic generation response decreases from 1.4 to 0.17 α-SiO2 powder standard units. The luminescence spectra of Ca10.5–1.5xYbx(PO4)7 point to two structural Yb3+ positions in full agreement with the structural data. The intensity of the luminescence emission line at ∼975 nm due to the 2F5/2 → 2F7/2 transition reaches the maximum at x = 0.667 in Ca10.5–1.5xYbx(PO4)7. The Yb3+ luminescence spectra studied as a function of the chemical composition 0 |
| Databáze: | OpenAIRE |
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